Display device

ABSTRACT

A display device includes: a display panel including a first display area including first sub-pixels to display an image, and a second display area including second sub-pixels and a transmission area adjacent to the second sub-pixels; and an optical device overlapping the second display area of the display panel and configured to detect light incident through the transmission area. Each of the second sub-pixels includes: a first contact electrode; a second contact electrode located apart from the first contact electrode; and a light emitting element between the first contact electrode and the second contact electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2020-0069513, filed on Jun. 9, 2020 in the KoreanIntellectual Property Office (KIPO), the entire content of which isincorporated by reference herein.

BACKGROUND 1. Field

Aspects of embodiments of the present invention relate to a displaydevice.

2. Description of the Related Art

With the development of information society, requirements for displaydevices for displaying images have increased in various forms. Forexample, display devices are applied to various electronic appliances,such as smartphones, digital cameras, notebook computers, navigators,and smart televisions.

A display device may include a display panel including a plurality ofpixels connected to scan lines, data lines, and power lines to displayan image. Further, the display device may include various opticaldevices, such as an image sensor for photographing an image on a frontsurface of the display device, a proximity sensor for detecting whethera user is located close to the front surface of the display device, anilluminance sensor for detecting the illuminance of the front surface ofthe display device, and an iris sensor for recognizing a user's iris.

The optical device may be provided in a hole formed in the front surfaceof the display device, the hole not overlapping the display panel. Asdisplay devices are applied to various electronic devices, displaydevices having various designs are needed. For example, in the case of asmartphone, there is a demand for a display device capable of widening adisplay area by omitting a hole formed in the front surface of thedisplay device. However, in a case in which optical devices are arrangedto overlap the display panel, the optical devices are covered by pixelsof the display panel, scan lines, data lines, and power lines, and,thus, light incident on the optical devices may be reduced. Thus, thefunction of the optical device may be deteriorated.

SUMMARY

According to an aspect of some embodiments of the present disclosure, adisplay device which can prevent or substantially prevent light incidenton an optical device from being reduced even when the optical device isdisposed to overlap a display panel is provided.

However, embodiments of the present disclosure are not limited to thoseset forth herein. The above and other aspects of embodiments of thepresent disclosure will become more apparent to one of ordinary skill inthe art to which the present disclosure pertains by referencing thedetailed description of the present disclosure given below.

According to one or more embodiments of the present disclosure, adisplay device comprises: a display panel including a first display areaincluding first sub-pixels to display an image, and a second displayarea including second sub-pixels and a transmission area adjacent to thesecond sub-pixels; and an optical device overlapping the second displayarea of the display panel and configured to detect light incidentthrough the transmission area. Each of the second sub-pixels includes: afirst contact electrode; a second contact electrode located apart fromthe first contact electrode; and a light emitting element between thefirst contact electrode and the second contact electrode.

According to one or more embodiments of the present disclosure, adisplay device comprises: a display panel including a first display areaincluding first sub-pixels to display an image, and a second displayarea including second sub-pixels and a transmission area adjacent to thesecond sub-pixels; and an optical device overlapping the second displayarea of the display panel and configured to detect light incidentthrough the transmission area. Each of the first sub-pixels includes afirst light emitting electrode, a second light emitting electrode on thefirst light emitting electrode, and a light emitting layer between thefirst light emitting electrode and the second light emitting electrode,and each of the second sub-pixels includes a first contact electrode, asecond contact electrode located apart from the first contact electrode,and a light emitting element between the first contact electrode and thesecond contact electrode.

According to one or more embodiments of the present disclosure, adisplay device comprises: a first substrate; a first thin filmtransistor on the first substrate and including a first gate electrode,a first source electrode, and a first drain electrode; a second thinfilm transistor on the first substrate and including a second gateelectrode, a second source electrode, and a second drain electrode; afirst electrode electrically connected to the first source electrode orfirst drain electrode of the first thin film transistor; a lightemitting layer on the first electrode; a second electrode on the lightemitting layer; an encapsulation layer on the second electrode; a sensorelectrode on the encapsulation layer; a first alignment electrodeelectrically connected to the second source electrode or second drainelectrode of the second thin film transistor; and a second lightemitting element electrically connected to the first alignmentelectrode. The sensor electrode and the first alignment electrode aremade of a same material.

According to the aforementioned and other example embodiments of thepresent disclosure, since the second display area includes pixels and atransmission area, when optical devices are arranged on a back surfaceof the second display area of a display panel, light incident on a frontsurface of the display panel may be incident on the optical devicesthrough the transmission areas.

According to the aforementioned and other example embodiments of thepresent disclosure, a number of light emitting elements of the pixel inthe second display area may be greater than a number of light emittingelements of the pixel in the first display area. In this case, a maximumluminance of the pixels in the second display area may be higher than amaximum luminance of the pixels in the first display area. Accordingly,a difference between the maximum luminance of the first display area andthe maximum luminance of the second display area due to the transmissionarea can be minimized or reduced.

According to the aforementioned and other example embodiments of thepresent disclosure, when the area of the pixel in the second displayarea is reduced, the area of the transmission area may be increased.Therefore, the amount of light incident on the optical devices arrangedon the back surface of the second display area of the display panelthrough the transmission areas can be increased. Thus, optical sensingof the optical devices may be improved.

According to the aforementioned and other example embodiments of thepresent disclosure, when the first alignment electrode and the secondalignment electrode are disposed on a same layer as the sensingelectrodes and the driving electrodes and are made of a same material asthe sensing electrodes and the driving electrodes, the first alignmentelectrode, the second alignment electrode, the sensing electrodes, andthe driving electrodes may be formed by one mask process. Therefore, anyone of the mask process for forming the first alignment electrode andthe second alignment electrode and the mask process for forming thesensing electrodes and the driving electrodes can be omitted, therebyreducing a manufacturing cost.

According to the aforementioned and other example embodiments of thepresent disclosure, when the sensor electrode is disposed on a samelayer as the second contact electrode and is made of a same material asthe second contact electrode, the sensor electrode and the secondcontact electrode can be formed by one mask process. Therefore, any oneof the mask process for forming the sensor electrode and the maskprocess for forming the second contact electrode can be omitted, therebyreducing a manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present disclosure willbecome more apparent by describing some example embodiments thereof withreference to the attached drawings, in which:

FIG. 1 is a perspective view of a display device according to anembodiment;

FIG. 2 is an exploded perspective view of a display device according toan embodiment;

FIG. 3 is an exploded perspective view of a display device according toanother embodiment;

FIG. 4A is a view illustrating a display panel, a display circuit board,a display driving circuit, and a touch driving circuit according to anembodiment;

FIG. 4B is a view illustrating a display panel, a display circuit board,a display driving circuit, and a touch driving circuit according toanother embodiment;

FIG. 5 is a layout view illustrating a first display area of a displaypanel according to an embodiment;

FIG. 6 is an example view illustrating a light emitting elementaccording to an embodiment;

FIG. 7 is a layout view illustrating a second display area of a displaypanel according to an embodiment,

FIG. 8 is a layout view illustrating a second display area of a displaypanel according to another embodiment;

FIG. 9 is a cross-sectional view illustrating an example of a displaypanel taken along the lines I-I′ and II-II′ of FIG. 7;

FIG. 10 is a layout view illustrating a first display area of a displaypanel according to another embodiment;

FIG. 11 is a cross-sectional view illustrating an example of a displaypanel taken along the line III-III′ of FIG. 10;

FIG. 12 is a cross-sectional view illustrating another example of adisplay panel taken along the lines I-I′ and II-II′ of FIG. 7;

FIG. 13 is a layout view illustrating a first display area of a displaypanel according to another embodiment;

FIG. 14 is a layout view illustrating a second display area of a displaypanel according to another embodiment;

FIG. 15 is a cross-sectional view illustrating another example of adisplay panel taken along the line IV-IV′ of FIG. 13;

FIG. 16 is a cross-sectional view illustrating an example of a displaypanel taken along the lines V-V′ and VI-VI′ of FIG. 14;

FIG. 17 is a cross-sectional view illustrating another example of adisplay panel taken along the lines V-V and VI-VI′ of FIG. 14;

FIG. 18 is a cross-sectional view illustrating another example of adisplay panel taken along the line IV-IV′ of FIG. 13;

FIG. 19 is a cross-sectional view illustrating another example of adisplay panel taken along the lines V-V and VI-VI′ of FIG. 14;

FIGS. 20 to 22 are perspective views of a display device according toanother embodiment; and

FIGS. 23 and 24 are perspective views of a display device according toanother embodiment.

DETAILED DESCRIPTION

The present disclosure will now be described more fully herein withreference to the accompanying drawings, in which some exampleembodiments of the disclosure are shown. This disclosure may, however,be embodied in different forms and should not be construed as beinglimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the disclosure to those skilled in theart. The same reference numbers indicate the same or like componentsthroughout the specification. In the attached figures, the thicknessesof layers and regions may be exaggerated for clarity.

Herein, the use of the term “may,” when describing embodiments of thepresent disclosure, refers to “one or more embodiments of the presentdisclosure.” As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. As usedherein, the singular forms “a,” “an,” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. As used herein, expressions such as “at least one of,” “oneof,” and “selected from,” when preceding a list of elements, modify theentire list of elements and do not modify the individual elements of thelist.

It is to be understood that when an element or layer is referred to asbeing “on,” “connected to,” “coupled to,” or “adjacent to” anotherelement or layer, it may be directly on, connected to, coupled to, oradjacent to the other element or layer, or one or more interveningelements or layers may be present. In contrast, when an element or layeris referred to as being “directly on,” “directly connected to,”“directly coupled to,” or “immediately adjacent to” another element orlayer, there are no intervening elements or layers present. As usedherein, the terms “substantially,” “about,” and similar terms are usedas terms of approximation and not as terms of degree, and are intendedto account for the inherent deviations in measured or calculated valuesthat would be recognized by those of ordinary skill in the art.

As used herein, phrases such as “a plan view” may refer to a view fromtop or from a direction normal to the display area of the displaydevice.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” “bottom,” “top,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It is to beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” or “over” theother elements or features. Thus, the term “below” may encompass both anorientation of above and below. The device may be otherwise oriented(e.g., rotated 90 degrees or at other orientations), and the spatiallyrelative descriptors used herein should be interpreted accordingly.

Any numerical range recited herein is intended to include all sub-rangesof the same numerical precision subsumed within the recited range. Forexample, a range of “1.0 to 10.0” is intended to include all subrangesbetween (and including) the recited minimum value of 1.0 and the recitedmaximum value of 10.0, that is, having a minimum value equal to orgreater than 1.0 and a maximum value equal to or less than 10.0, suchas, for example, 2.4 to 7.6. Any maximum numerical limitation recitedherein is intended to include all lower numerical limitations subsumedtherein and any minimum numerical limitation recited in thisspecification is intended to include all higher numerical limitationssubsumed therein. Accordingly, Applicant reserves the right to amendthis specification, including the claims, to expressly recite anysub-range subsumed within the ranges expressly recited herein.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which the present disclosure belongs. Itis to be further understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand/or the present disclosure, and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Herein, some example embodiments of the present disclosure will bedescribed with reference to the attached drawings.

FIG. 1 is a perspective view of a display device according to anembodiment; and FIG. 2 is an exploded perspective view of a displaydevice according to an embodiment.

Referring to FIGS. 1 and 2, a display device 10 according to anembodiment may be applied to a portable electronic appliance, such as amobile phone, a smartphone, a tablet personal computer (tablet PC), amobile communication terminal, an electronic notebook, an e-book, aportable multimedia player (PMP), a navigator, or an ultra-mobile PC(UMPC). Alternatively, the display device 10 according to an embodimentmay be applied to a display unit of a television, a notebook, a monitor,a billboard, or internet of things (IOT). Alternatively, the displaydevice 10 according to an embodiment may be applied to a wearabledevice, such as a smart watch, a watch phone, an eyeglass display, or ahead mounted display (HMD). Alternatively, the display device 10according to an embodiment may be applied to a center informationdisplay placed in a car instrument panel, a car center fascia or acarbon dashboard, a room mirror display replacing a car side mirror, ora display placed on a back surface of a front seat as an entertainmentdevice for a back seat of a car.

In this specification, a first direction (X-axis direction) is adirection parallel to short sides of the display device 10, for example,and may be a horizontal direction of the display device 10. A seconddirection (Y-axis direction) is a direction parallel to long sides ofthe display device 10, for example, and may be a vertical direction ofthe display device 10. A third direction (Z-axis direction) may be athickness direction of the display device 10.

In an embodiment, the display device 10 may have a planar shape similarto a rectangular shape. For example, as shown in FIG. 1, the displaydevice 10 may have a planar shape similar to a rectangular planar shapehaving short sides in the first direction (X-axis direction) and longsides in the second direction (Y-axis direction). An edge where theshort side in the first direction (X-axis direction) meets the long sidein the second direction (Y-axis direction) may be formed to have arounded shape of a curvature (e.g., a predetermined curvature) or have aright angle shape. However, the planar shape of the display device 10 isnot limited to a rectangular shape, and may be formed in anotherpolygonal shape, circular shape, or elliptical shape.

In an embodiment, the display device 10 may be formed flat. In anotherembodiment, the display device 10 may be formed such that two sidesfacing each other are bent. For example, the display device 10 may beformed such that left and right sides are bent. Alternatively, thedisplay device 10 may be formed such that upper, lower, left, and rightsides are all bent.

The display device 10 according to an embodiment includes a cover window100, a display panel 300, a display circuit board 310, a display drivingcircuit 320, a bracket 600, a main circuit board 700, optical devices740, 750, 760, and 770, and a lower cover 900.

The cover window 100 may be disposed on a front surface of the displaypanel 300 so as to cover the front surface of the display panel 300.Thus, the cover window 100 may protect the front surface of the displaypanel 300. In an embodiment, the cover window 100 may be attached to thefront surface of the display panel 300 using a transparent adhesivemember.

The cover window 100 is made of a transparent material, and, in anembodiment, may include glass or plastic. For example, when the coverwindow 100 includes glass, the cover window 100 may include ultra-thinglass (UTG) having a thickness of 0.1 mm or less. In an embodiment, whenthe cover window includes plastic, the cover window 100 may include atransparent polyimide film.

The display panel 300 may include a display area DA including a firstdisplay area DA1 and a second display area DA2. The first display areaDA1 includes pixels for displaying an image, and does not include atransmission area for transmitting light. In contrast, the seconddisplay area DA2 may include not only pixels for displaying an image,but also a transmission area for transmitting light. Therefore, thelight transmittance of the second display area DA2 may be higher thanthat of the first display area DA1.

The second display area DA2 may overlap the optical devices 740, 750,760, and 770 in the third direction (Z-axis direction). Therefore, lightpassing through the second display area DA2 may be incident on theoptical devices 740, 750, 760, and 770. Thus, each of the opticaldevices 740, 750, 760, and 770 may detect light incident from the frontsurface of the display device 10 even though it is disposed to overlapthe display panel 300.

The display panel 300 may be a light emitting display panel including alight emitting element. For example, the display panel 300 may be anorganic light emitting display panel using an organic light emittingdiode including an organic light emitting layer, an ultra-small LEDdisplay panel using micro LED or nano LED, a quantum dot light emittingdisplay panel using a quantum dot light emitting diode including aquantum dot light emitting layer, or an inorganic light emitting displaypanel using an inorganic light emitting diode including an inorganicsemiconductor.

The first display area DA1 and the second display area DA2 may includethe same light emitting element or different light emitting elementsfrom each other. For example, both the first display area DA1 and thesecond display area DA2 may include micro LEDs or nano LEDs. In anembodiment, the first display area DA1 includes an organic lightemitting diode, and the second display area DA2 may include a micro LEDor nano LED.

The display circuit board 310 and the display driving circuit 320 may beattached to a side of the display panel 300. The display circuit board310 may be a flexible printed circuit board that may be bent, a rigidprinted circuit board that is not easily bent due to rigidity, or acomposite printed circuit board including both the rigid printed circuitboard and the flexible printed circuit board.

The display driving circuit 320 may receive control signals and powervoltages, and may generate and output signals and voltages for drivingthe display panel 300. In an embodiment, the display driving circuit 320may be formed as an integrated circuit (IC). The display driving circuit320 may be attached onto the display panel 300 by a chip on glass (COG)method, a chip on plastic (COP) method, or an ultrasonic bonding method,but the present invention is not limited thereto. For example, thedisplay driving circuit 320 may be attached onto the display circuitboard 310.

In an embodiment, a touch driving circuit 330 may be disposed on thedisplay circuit board 310. The touch driving circuit 330 may be formedas an integrated circuit, and may be attached to a surface of thedisplay circuit board 310. The touch driving circuit 330 may beelectrically connected to touch electrodes of a touch sensor layer ofthe display panel 300 through the display circuit board 310. The touchdriving circuit 330 may output touch driving signals to the touchelectrodes, and may sense voltages charged in the capacitances of thetouch electrodes.

The touch driving circuit 330 may generate touch data according to achange in the electrical signal sensed at each of the sensor electrodesand transmit the touch data to a main processor 710, and the mainprocessor 710 may analyze the touch data to calculate touch coordinateswhere a touch has occurred. The touch may include a contact touch and aproximity touch. The contact touch indicates that an object, such as ahuman finger or a pen, is in direct contact with the cover window 100disposed on the sensor electrode layer. The proximity touch indicatesthat, like hovering, an object, such as a human finger or a pen, islocated close to the cover window 100.

In an embodiment, a power supply unit for supplying display drivingvoltages for driving the display driving circuit 320 may be additionallydisposed on the display circuit board 310.

The bracket 600 may be disposed under the display panel 300. The bracket600 may include a plastic, a metal, or both a plastic and a metal. In anembodiment, the bracket 600 may be provided with a first camera holeCMH1 into which a first camera sensor 720 is inserted, a battery hole BHin which a battery is disposed, a cable hole CAH through which a cable314 connected to the display circuit board 310 passes, and a lighttransmitting hole SH in which the optical devices 740, 750, 760, and 770are disposed. In another embodiment, the bracket 600 may be formed notto overlap the second display area DA2 of the display panel 300 insteadof including the light transmitting hole SH.

The main circuit board 700 and a battery 790 may be disposed under thebracket 600. The main circuit board 700 may be a printed circuit boardor a flexible printed circuit board.

The main circuit board 700 may include the main processor 710, the firstcamera sensor 720, a main connector 730, and the optical devices 740,750, 760, 770. In an embodiment, the optical devices 740, 750, 760, and770 may include a proximity sensor 740, an illuminance sensor 750, aniris sensor 760, and a second camera sensor 770.

In an embodiment, the first camera sensor 720 may be disposed on thefront and back surfaces of the main circuit board 700, the mainprocessor 710 may be disposed on the front surface of the main circuitboard 700, and the main connector 730 may be disposed on the backsurface of the main circuit board 700. The proximity sensor 740, theilluminance sensor 750, the iris sensor 760, and the second camerasensor 770 may be disposed on the front surface of the main circuitboard 700.

The main processor 710 may control all of the functions of the displaydevice 10. For example, the main processor 710 may output digital videodata to the display driving unit 320 through the display circuit board310 such that the display panel 300 displays an image. Further, the mainprocessor 710 may receive touch data from the touch driving unit 330,determine a user's touch coordinates, and then execute an applicationindicated by an icon displayed on the user's touch coordinates. Further,the main processor 710 may convert first image data input from the firstcamera sensor 720 into digital video data and output the digital videodata to the display driving circuit 320 through the display circuitboard 310, thereby displaying an image photographed by the first camerasensor 720 on the display panel 300. Further, the main processor 710 maycontrol the display device 10 according to sensor signals input from theproximity sensor 740, the illuminance sensor 750, the iris sensor 760,and the second camera sensor 770.

The main processor 710 may determine whether an object is located closeto the front surface of the display device 10 according to the proximitysensor signal input from the proximity sensor 740. When an object islocated close to the front surface of the display device 10 in a callmode in which a user speaks with another party using the display device10, the main processor 710 may not execute an application indicated byan icon displayed on the user's touch coordinates even if the touch isexecuted by the user.

The main processor 710 may determine the brightness of the front surfaceof the display device 10 according to the illuminance sensor signalinput from the illuminance sensor 750. The main processor 710 may adjustthe luminance of an image displayed by the display panel 300 accordingto the brightness of the front surface of the display device 10.

The main processor 710 may determine whether an iris image of a user isthe same as the iris image previously stored in the memory according toan iris sensor signal input from the iris sensor 760. When the irisimage of the user is the same as the iris image previously stored in thememory, the main processor 710 may unlock the display device 10 anddisplay a home screen on the display panel 300.

The main processor 710 may generate digital video data according to thesecond image data input from the second camera sensor 770. The mainprocessor 710 may output the digital video data to the display drivingcircuit 320 through the display circuit board 310, thereby displaying animage photographed by the second camera sensor 770.

The first camera sensor 720 processes an image frame such as a stillimage or a moving image obtained by the image sensor and outputs theprocessed image frame to the main processor 710. In an embodiment, thefirst camera sensor 720 may be a CMOS image sensor or a CCD sensor. Thefirst camera sensor 720 may be exposed to a back surface of the lowercover 900 by a second camera hole CMH2, and thus an object or backgrounddisposed under the display device 10 may be photographed.

The cable 314 having passed through the cable hole CAH of the bracket600 may be connected to the main connector 730. Thus, the main circuitboard 700 may be electrically connected to the display circuit board310.

The proximity sensor 740 is a sensor for detecting whether an object islocated close to the front surface of the display device 10. In anembodiment, the proximity sensor 740 may include a light source thatoutputs light and a light receiver that receives light reflected by anobject. The proximity sensor 740 may determine whether an object locatedclose to the front surface of the display device 10 exists according toan amount of light reflected by the object. Since the proximity sensor740 is disposed to overlap the light transmitting hole SH, the seconddisplay area DA2 of the display panel 300, and a light transmittingportion of the cover window 100 in the third direction (Z-axisdirection), the proximity sensor 740 may generate a proximity sensorsignal according to whether an object located close to the front surfaceof the display device 10 exists, and may output the proximity sensorsignal to the main processor 710.

The illuminance sensor 750 is a sensor for detecting the brightness ofthe front surface of the display device 10. In an embodiment, theilluminance sensor 750 may include a resistor having a resistance valuethat changes according to a brightness of incident light. Theilluminance sensor 750 may determine the brightness of the front surfaceof the display device 10 according to the resistance value of theresistor. Since the illuminance sensor 750 is disposed to overlap thelight transmitting hole SH, the second display area DA2 of the displaypanel 300, and the light transmitting portion of the cover window 100 inthe third direction (Z-axis direction), the illuminance sensor 750 maygenerate an illuminance sensor signal according to the brightness of thefront surface of the display device 10, and may output the illuminancesensor signal to the main processor 710.

The iris sensor 760 is a sensor for detecting whether an image of auser's iris is the same as an iris image previously stored in thememory. Since the iris sensor 760 is disposed to overlap the lighttransmitting hole SH, the second display area DA2 of the display panel300, and the light transmitting portion of the cover window 100 in thethird direction (Z-axis direction), a user's iris disposed on thedisplay device 10 may be photographed. The iris sensor 760 may generatean iris sensor signal according to whether an image of the user's irisis the same as the iris image previously stored in the memory, and mayoutput the iris sensor signal to the main processor 710.

The second camera sensor 770 processes an image frame such as a stillimage or a moving image obtained by the image sensor and output theprocessed image frame to the main processor 710. In an embodiment, thesecond camera sensor 770 may be a CMOS image sensor or a CCD sensor. Anumber of pixels in the second camera sensor 770 may be smaller than anumber of pixels in the first camera sensor 720, and the size of thesecond camera sensor 770 may be smaller than the size of the firstcamera sensor 720. Since the second camera sensor 770 is disposed tooverlap the light transmitting hole SH, the second display area DA2 ofthe display panel 300, and the light transmitting portion of the coverwindow 100 in the third direction (Z-axis direction), the second camerasensor 770 may photograph an object or background disposed on thedisplay device 10.

In an embodiment, the battery 790 may be disposed so as not to overlapthe main circuit board 700 in the third direction (Z-axis direction).The battery 790 may overlap the battery hole BH of the bracket 600.

In an embodiment, the main circuit board 700 may be further providedwith a mobile communication module capable of transmitting and receivingradio signals with at least one of a base station, an external terminal,and a server on a mobile communication network. The radio signals mayinclude any of various types of data according to transmission andreception of a voice call signal, a video call signal, or atext/multimedia message.

The lower cover 900 may be disposed under the main circuit board 700 andthe battery 790. The lower cover 900 may be engaged and fixed to thebracket 600. The lower cover 900 may form a back surface appearance ofthe display device 10. In an embodiment, the lower cover 900 may includea plastic, a metal, or both a plastic and a metal.

The lower cover 900 may be provided with the second camera hole CMH2through which a back surface of the first camera sensor 720 is exposed.However, the position of the first camera sensor 720 and the positionsof the first and second camera holes CMH1 and CMH2 corresponding to thefirst camera sensor 720 are not limited to the example embodiment shownin FIG. 2.

FIG. 3 is an exploded perspective view of a display device according toanother embodiment.

The embodiment of FIG. 3 is different from the embodiment of FIG. 2 inthat the optical devices 740, 750, 760, and 770 are attached to the backsurface of the display panel 300. In FIG. 3, differences from theembodiment of FIG. 2 will be mainly described.

Referring to FIG. 3, in an embodiment, each of the proximity sensor 740,the illuminance sensor 750, the iris sensor 760, and the second camerasensor 770 may be attached to a rear surface of the display panel 300using a transparent adhesive member. In this case, the bracket 600 maynot include the light transmitting hole SH.

FIG. 4A is a view illustrating a display panel, a display circuit board,a display driving circuit, and a touch driving circuit according to anembodiment.

Referring to FIG. 4A, the display panel 300 may be a rigid display panelthat is not easily bent due to rigidity, or a flexible display panelthat is easily bent, folded, or rolled due to flexibility. For example,the display panel 300 may be a foldable display panel that can be foldedand unfolded, a curved display panel in which a display surface iscurved, a bent display panel in which an area other than the displaysurface is bent, a rollable display device that can be rolled andunrolled, or a stretchable display panel that can be stretched.

The display panel 300 may include a main area MA and a sub-area SBAprotruding from a side of the main area MA. The main area MA may includea display area DA displaying an image and a non-display area NDA that isan area peripheral to the display area DA. The display area DA mayoccupy most of the main area MA. In an embodiment, the display area DAmay be disposed at the center of the main area MA, and the non-displayarea NDA may be an area outside the display area DA. In an embodiment,the non-display area NDA may be disposed to surround the display areaDA. The non-display area NDA may be defined as an edge area of thedisplay panel 300.

The display area DA may include a first display area DA1 and a seconddisplay area DA2. The first display area DA1 may occupy most of thedisplay area DA. The second display area DA2 may be at least partiallysurrounded by the first display area DA1. The second display area DA2may be disposed on at least a part of an edge of the display panel 300.For example, the second display area DA2 may be disposed on at least apart of an upper edge, a lower edge, a left edge, or a right edge of thedisplay panel 300, but the present invention is not limited thereto.

In an embodiment, the second display area DA2 may have a rectangularplanar shape. When the second display area DA2 is disposed on at least apart of the upper edge or lower edge of the display panel 300, thelength of the second display area DA2 in the first direction (X-axisdirection) may be longer than the length of the second display area DA2in the second direction (Y-axis direction). In another embodiment, whenthe second display area DA2 is disposed on at least a part of the leftedge or right edge of the display panel 300, the length of the seconddisplay area DA2 in the second direction (Y-axis direction) may belonger than the length of the second display area DA2 in the firstdirection (X-axis direction).

The sub-area SBA may protrude from a side of the main area MA in thesecond direction (Y-axis direction). The length of the sub-area SBA inthe second direction (Y-axis direction) may be smaller than the lengthof the main area MA in the second direction (Y-axis direction). Thelength of the sub-area SBA in the first direction (X-axis direction) maybe smaller than the length of the main area MA in the first direction(X-axis direction), or may be substantially the same as the length ofthe main area MA in the first direction (X-axis direction). The sub-areaSBA may be bent, and may be disposed on the back surface of thesubstrate SUB. In this case, the sub-area SBA may overlap the main areaMA in the third direction (Z-axis direction).

The display circuit board 310 and the display driving circuit 320 may beattached to the sub-area SBA of the display panel 300. In an embodiment,the display circuit board 310 may be attached to pads of the sub-areaSBA of the display panel 300 using a low-resistance and high-reliabilitymaterial such as an anisotropic conductive film or a self-assemblyanisotropic conductive paste (SAP).

FIG. 4B is a view illustrating a display panel, a display circuit board,a display driving circuit, and a touch driving circuit according toanother embodiment.

The embodiment of FIG. 4B is different from the embodiment of FIG. 4A inthat the display panel includes a plurality of second display areas DA2.In FIG. 4B, differences from the embodiment of FIG. 4A will be mainlydescribed.

Referring to FIG. 4B, the second display areas DA2 may be arranged to bespaced apart from each other. When the second display areas DA2 arearranged on at least a part of the upper edge or lower edge of thedisplay panel 300, the second display areas DA2 may be arranged in thefirst direction (X-axis direction). When the second display areas DA2are arranged on at least a part of the left edge or right edge of thedisplay panel 300, the second display areas DA2 may be arranged in thesecond direction (Y-axis direction). In an embodiment, each of thesecond display areas DA2 may be completely surrounded by the firstdisplay area DA1.

The second display areas DA2 may overlap the optical devices 740, 750,760, and 770 in the third direction (Z-axis direction), respectively.For example, one of the second display areas DA2 may overlap theproximity sensor 740 in the third direction (Z-axis direction), anotherof the second display areas DA2 may overlap the illuminance sensor 750in the third direction (Z-axis direction), another of the second displayareas DA2 may overlap the iris sensor 760 in the third direction (Z-axisdirection), and another of the second display areas DA2 may overlap thesecond camera sensor 770 in the third direction (Z-axis direction). Theproximity sensor 740, the illuminance sensor 750, the iris sensor 760,and the second camera sensor 770 may detect light incident from thefront surface of the display device 10 through the second display areasDA2.

Although it is illustrated in FIG. 4B that the display area DA includesfour second display areas DA2, the present invention is not limitedthereto. The number of the second display areas DA2 may depend on thenumber of optical devices 740, 750, 760, and 770. For example, thesecond display areas DA2 may be disposed to correspond one-to-one withthe optical devices 740, 750, 760, and 770.

Although it is illustrated in FIG. 4B that the second display areas DA2have a circular planar shape, the present invention is not limitedthereto. For example, each of the second display areas DA2 may have apolygonal or elliptical planar shape. As shown in FIG. 4B, the seconddisplay areas DA2 may have a same size as one another, but the presentinvention is not limited thereto. The second display areas DA2 may havedifferent sizes from each other.

FIG. 5 is a layout view illustrating a first display area of a displaypanel according to an embodiment.

Referring to FIG. 5, the first display area DA1 may include pixels PXincluding a first sub-pixel SP1, a second sub-pixel SP2, and a thirdsub-pixel SP3. The first sub-pixel SP1 may include a light emittingelement 175 that emits first light, the second sub-pixel SP2 may includea light emitting element 175 that emits second light, and the thirdsub-pixel SP3 may include a light emitting element 175 that emits thirdlight.

In the first display area DA1, the first sub-pixels SP1, the secondsub-pixels SP2, and the third sub-pixels SP3 may be alternately arrangedin the first direction (X-axis direction). The first sub-pixels SP1 maybe arranged in parallel in the second direction (Y-axis direction), thesecond sub-pixels SP2 may be arranged in parallel in the seconddirection (Y-axis direction), and the third sub-pixels SP3 may bearranged in parallel in the second direction (Y-axis direction).

Each of the first sub-pixels SP1, the second sub-pixels SP2, and thethird sub-pixels SP3 may include a first alignment electrode 171, asecond alignment electrode 173, a contact electrode 174, and lightemitting elements 175.

The first alignment electrode 171 is a pixel electrode separated orspaced apart for each of the sub-pixels SP1, SP2, and SP3, and thesecond alignment electrode 173 may be a common electrode commonlyconnected to the sub-pixels SP1, SP2, and SP3. One of the firstalignment electrode 171 and the second alignment electrode 173 may be ananode electrode of the light emitting element 175 and the other of thefirst alignment electrode 171 and the second alignment electrode 173 maybe a cathode electrode of the light emitting element 175.

The first alignment electrode 171 may include a first electrode stemportion 171S and at least one first electrode branch portion 171Bbranched from the first electrode stem portion 171S and extending in thesecond direction (Y-axis direction).

The first electrode stem portion 171S of one sub-pixel of the sub-pixelsSP1, SP2, and SP3 may be electrically separated from the first electrodestem portion 171S of another sub-pixel adjacent to the one sub-pixel inthe first direction (X-axis direction). The first electrode stem portion171S of any one sub-pixel may be disposed to be spaced apart from thefirst electrode stem portion 171S of another sub-pixel adjacent to theone sub-pixel in the first direction (X-axis direction). In anembodiment, the first electrode stem part 171S may be connected to asource electrode or a drain electrode of a first thin film transistorthrough a first electrode contact hole CNTD.

The first electrode branch portion 171B may be disposed to be spacedapart from another first electrode branch portion 171B in the firstdirection (X-axis direction). At least one second electrode branchportion 173B of the second alignment electrode 173 may be disposedbetween adjacent first electrode branch portions 171B in the firstdirection (X-axis direction).

The second alignment electrode 173 may include a second electrode stemportion 173S extending in the first direction (X-axis direction) and asecond electrode branch portion 173B branched from the second electrodestem portion 173S and extending in the second direction (Y-axisdirection).

The second electrode stem portion 173S of one sub-pixel of thesub-pixels SP1, SP2, and SP3 may be connected to the second electrodestem portion 173S of another sub-pixel adjacent to the one sub-pixel inthe first direction (X-axis direction). The second electrode stemportion 173S may be disposed to cross the sub-pixels SP1, SP2, and SP3in the first direction (X-axis direction).

The second electrode branch portion 173B may be disposed to be spacedapart from the first electrode branch portion 171B in the firstdirection (X-axis direction). The second electrode branch portion 173Bmay be disposed between the first electrode branch portions 171B in thefirst direction (X-axis direction).

Although it is illustrated in FIG. 5 that the first electrode branchportion 171B and the second electrode branch portion 173B extend in thesecond direction (Y-axis direction), the present invention is notlimited thereto. For example, each of the first electrode branch portion171B and the second electrode branch portion 173B may have a partiallycurved or bent shape. In another embodiment, one electrode of the firstelectrode branch portion 171B and the second electrode branch portion173B may be disposed to surround the other electrode thereof. Forexample, the second electrode branch portion 173B may have a circularplanar shape and be disposed to surround the first electrode branchportion 171B, and an annular hole may be formed between the firstelectrode branch portion 171B and the second electrode branch portion173B. That is, when the first electrode branch portion 171B and thesecond electrode branch portion 173B are spaced apart from each otherand a space for providing the light emitting element 175 is formedbetween the first electrode branch portion 171B and the second electrodebranch portion 173B, each of the first electrode branch portion 171B andthe second electrode branch portion 173B may be formed to have anysuitable shape.

The contact electrode 174 may include a first contact electrode 174 aand a second contact electrode 174 b. The first contact electrode 174 aand the second contact electrode 174 b may extend in the seconddirection (Y-axis direction).

The first contact electrode 174 a may be disposed on the first electrodebranch portion 171B and may be in contact with the first electrodebranch portion 171B. The first contact electrode 174 a may be in contactwith one end of the light emitting element 175. The first contactelectrode 174 a may be disposed between the first electrode branchportion 171B and the light emitting element 175. Accordingly, the lightemitting element 175 may be electrically connected to the firstalignment electrode 171 through the first contact electrode 174 a.

The second contact electrode 174 b may be disposed on the secondelectrode branch portion 173B and may be in contact with the secondelectrode branch portion 173B. The second contact electrode 174 b may bein contact with the other end of the light emitting element 175. Thesecond contact electrode 174 b may be disposed between the secondelectrode branch portion 173B and the light emitting element 175.Accordingly, the light emitting element 175 may be electricallyconnected to the second alignment electrode 173 through the secondcontact electrode 174 b.

In an embodiment, the width of the first contact electrode 174 a (or thelength of the first contact electrode 174 a in the first direction(X-axis direction)) may be greater than the width of the first electrodebranch portion 171B (or the length of the first electrode branch portion171B in the first direction (X-axis direction)), and the width of thesecond contact electrode 174 b (or the length of the second contactelectrode 174 b in the first direction (X-axis direction)) may begreater than the width of the second electrode branch portion 173B (orthe length of the second electrode branch portion 173B in the firstdirection (X-axis direction)).

Each of the light emitting elements 175 may be disposed between thefirst contact electrode 174 a and the second contact electrode 174 b.One end of each of the light emitting elements 175 may be in contactwith the first contact electrode 174 a, and the other end thereof may bein contact with the second contact electrode 174 b.

The plurality of light emitting elements 175 may be arranged to bespaced apart from each other. In an embodiment, the plurality of lightemitting elements 175 may be substantially aligned in parallel with eachother. The plurality of light emitting elements 175 may be arranged inthe second direction (Y-axis direction).

The light emitting element 175 may have a shape of a rod, wire, tube, orthe like. For example, the light emitting element 175 may have acylindrical shape or a rod shape. In another embodiment, the lightemitting element 175 may have a polyhedron shape, such as a cube or acuboid, or a polygonal column shape, such as a hexagonal column. Inanother embodiment, the light emitting element 175 may have a truncatedcone shape extending in a direction and having a partially inclinedouter surface. In an embodiment, the length of the light emittingelement 175 may be in a range of 1 μm to 10 μm or 2 μm to 6 μm, and, inan embodiment, in a range of 3 μm to 5 μm. In an embodiment, thediameter of the light emitting element 175 may be in a range of 300 nmto 700 nm, and the aspect ratio of the light emitting element 175 may be1.2 to 100.

Each of the light emitting elements 175 of the first sub-pixel SP1 mayemit a first light, each of the light emitting elements 175 of thesecond sub-pixel SP2 may emit a second light, and each of the lightemitting elements 175 of the third sub-pixel SP3 may emit a third light.In an embodiment, the first light may be red light having a centerwavelength band of 620 nm to 752 nm, the second light may be green lighthaving a center wavelength band of 495 nm to 570 nm, and the third lightmay be blue light having a center wavelength band of 450 nm to 495 nm.In another embodiment, the light emitting element 175 of the firstsub-pixel SP1, the light emitting element 175 of the second sub-pixelSP2, and the light emitting element 175 of the third sub-pixel SP3 mayemit light of a same or substantially same color.

FIG. 6 is an example view illustrating a light emitting elementaccording to an embodiment.

Referring to FIG. 6, in an embodiment, the light emitting element 175may include a first semiconductor layer 175 a, a second semiconductorlayer 175 b, an active layer 175 c, an electrode layer 175 d, and aninsulating film 175 e.

The first semiconductor layer 175 a may include, for example, an n-typesemiconductor having a first conductivity type. In an embodiment, thefirst semiconductor layer 175 a may include at least one of AlGaInN,GaN, AlGaN, InGaN, AlN, and InN, which are doped with an n-type dopant.For example, when the light emitting element 175 emits light in the bluewavelength band, the first semiconductor layer 175 a may include asemiconductor material having the formula AlxGayIn1-x-yN (0≤x≤1, 0≤y≤1,0≤x+y≤1). The first semiconductor layer 175 a may be doped with a firstconductivity type dopant, such as Si, Ge, or Sn. For example, the firstsemiconductor layer 175 a may include n-GaN doped with n-type Si.

The second semiconductor layer 175 b may include, for example, a p-typesemiconductor having a second conductivity type. In an embodiment, thesecond semiconductor layer 175 b may include at least one of AlGaInN,GaN, AlGaN, InGaN, AlN, and InN, which are doped with a p-type dopant.For example, when the light emitting element 175 emits light in the blueor green wavelength band, the second semiconductor layer 175 b mayinclude a semiconductor material having the formulaAlxGayIn1-x-yN(0≤x≤1, 0≤y≤1, 0≤x+y≤1). The second semiconductor layer175 b may be doped with a second conductivity type dopant, such as Mg,Zn, Ca, Se, or Ba. In an embodiment, the second semiconductor layer 175b may include p-GaN doped with p-type Mg.

The active layer 175 c is disposed between the first semiconductor layer175 a and the second semiconductor layer 175 b. The active layer 175 cmay include a material having a single or multiple quantum wellstructure. When the active layer 175 c includes a material having amultiple quantum well structure, the active layer 175 c may have astructure in which a plurality of quantum layers and a plurality of welllayers are alternately stacked. In another embodiment, the active layer175 c may have a structure in which a semiconductor material having alarge band gap energy and a semiconductor material having a small bandgap energy are alternately stacked, and may include Group 3 to 5semiconductor materials according to the wavelength band of emittedlight.

The active layer 175 c may emit light by the combination ofelectron-hole pairs according to electrical signals applied through thefirst semiconductor layer 175 a and the second semiconductor layer 175b. The light emitted by the active layer 175 c is not limited to lightin the blue wavelength band, but may emit light in the red and greenwavelength bands. For example, when the active layer 175 c emits lightin the blue wavelength band, the active layer 175 c may include amaterial such as AlGaN or AlGaInN. In an embodiment, when the activelayer 175 c is a multiple quantum well structure in which quantum layersand well layers are alternately stacked, the quantum layer may include amaterial such as AlGaN or AlGaInN, and the well layer may include amaterial such as GaN or AlInN. For example, the active layer 175 c mayinclude a quantum layer containing AlGaInN and a well layer containingAlInN, as described above, and the active layer 175 c may emit bluelight having a central wavelength band ranging from 450 nm to 495 nm.

The light emitted from the active layer 175 c may be emitted to bothside surfaces as well as a longitudinal outer surface of the lightemitting element 175. That is, the light emitted from the active layer175 c is not limited to one direction.

In an embodiment, the electrode layer 175 d may be an ohmic contactelectrode or a Schottky contact electrode. The light emitting element175 may include at least one electrode layer 175 d. When the lightemitting element 175 is electrically connected to the first alignmentelectrode 171 or the second alignment electrode 173, due to theelectrode layer 175 d, a resistance between the light emitting element175 and the first alignment electrode 171 or the second alignmentelectrode 173 may be reduced. In an embodiment, the electrode layer 175d may include at least one conductive metal material selected fromaluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag),indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin-zincoxide (ITZO). Further, the electrode layer 175 d may include asemiconductor material doped with an n-type or a p-type dopant. Theelectrode layer 175 d may include a same material or differentmaterials, but the present invention is not limited thereto.

In an embodiment, the insulating film 175 e is disposed to surround theouter surfaces of the first semiconductor layer 175 a, the secondsemiconductor layer 175 b, the active layer 175 c, and the electrodelayer 175 d. The insulating film 175 e protects the first semiconductorlayer 175 a, the second semiconductor layer 175 b, the active layer 175c, and the electrode layer 175 d. The insulating film 175 e may beformed to expose both ends of the light emitting element 175 in thelength direction. That is, one end of the first semiconductor layer 175a and one end of the electrode layer 175 d may be exposed without beingcovered by the insulating film 175 e. In an embodiment, the insulatingfilm 175 e may cover a part of the outer surface of the firstsemiconductor layer 175 a and a part of the outer surface of the secondsemiconductor layer 175 b in addition to the active layer 175 c, or maycover a part of the outer surface of the electrode layer 175 d inaddition to the active layer 175 c.

The insulating film 175 e may include any of materials having insulatingproperties, for example, silicon oxide (SiOx), silicon nitride (SiNx),silicon oxynitride (SiOxNy), aluminum nitride (AlN), and aluminum oxide(A₂O₃). The insulating film 175 e may prevent or substantially preventan electrical short that may occur when the active layer 175 c is indirect contact with the first alignment electrode 171 and the secondalignment electrode 173 transmitting electrical signals to the lightemitting element 175. Further, since the insulating film 175 e protectsthe outer surface of the light emitting elements 175 in addition to theactive layer 175 c, the insulating film 175 e may prevent orsubstantially prevent a decrease in light emission efficiency.

FIG. 7 is a layout view illustrating a second display area of a displaypanel according to an embodiment.

Referring to FIG. 7, the second display area DA2 may include pixels PXand transmission areas TA.

Each of the pixels PX may include a first sub-pixel SP1, a secondsub-pixel SP2, and a third sub-pixel SP3. Since the first sub-pixelsSP1, the second sub-pixels SP2, and the third sub-pixels SP3 may besubstantially the same as those described with reference to FIG. 5,further descriptions thereof will be omitted.

The transmission areas TA are areas through which light incident on thedisplay panel 300 passes. In an embodiment, the transmission areas TAmay be surrounded by pixels PX. In an embodiment, in the first direction(X-axis direction) and the second direction (Y-axis direction), thetransmission areas TA and the pixels PX may be alternately arranged. Forexample, the transmission areas TA and the pixels PX may be alternatelyarranged in the first direction (X-axis direction) and the seconddirection (Y-axis direction). Even when the optical devices 740, 750,760, and 770 are arranged on the back surface of the display panel 300,light incident on the front surface of the display panel 300 istransmitted to the optical devices 740, 750, 760, and 770 through thetransmission areas TA.

Since the second display area DA2 is provided with the transmissionareas TA, a number (for example, pixels per inch (PPI)) of sub-pixelsSP1, SP2, and SP3 per unit area in the second display area DA2 may besmaller than the number of sub-pixels SP1, SP2, and SP3 per unit area inthe first display area DA1. The unit area may be an area (e.g., apredetermined area) for calculating the number of pixels. For example,the unit area may be an area of a rectangular area corresponding to 1inch in the first direction (X-axis direction) and 1 inch in the seconddirection (Y-axis direction) on a plane. Since the number of sub-pixelsSP1, SP2, and SP3 per unit area in the second display area DA2 issmaller than the number of sub-pixels SP1, SP2, and SP3 per unit area inthe first display area DA1, the maximum luminance of the second displayarea DA2 may be lower than the maximum luminance of the first displayarea DA1.

In an embodiment, a number of the light emitting elements 175 in thepixel PX of the second display area DA2 may be larger than the number oflight emitting elements 175 in the pixel PX of the first display areaDA1. For example, a number of the light emitting elements 175 in each ofthe sub-pixels SP1, SP2, and SP3 of the second display area DA2 may belarger than a number of the light emitting elements 175 in each of thesub-pixels SP1, SP2, and SP3 of the first display area DA1. In thiscase, the maximum luminance of the pixel PX of the second display areaDA2 may be higher than the maximum luminance of the pixel PX of thefirst display area DA1. Therefore, a difference between the maximumluminance of the second display area DA2 and the maximum luminance ofthe first display area DA1 may be minimized or reduced.

FIG. 8 is a layout view illustrating a second display area of a displaypanel according to another embodiment.

The embodiment of FIG. 8 is different from the embodiment of FIG. 7 inthat an area of the pixel PX of the second display area DA2 is differentfrom an area of the pixel PX of the first display area DA1. In FIG. 8,differences from the embodiment of FIG. 7 will be mainly described.

Referring to FIG. 8, the area of the pixel PX of the second display areaDA2 may be smaller than the area of the pixel PX of the first displayarea DA1. The area of each of the sub-pixels SP1, SP2, and SP3 of thesecond display area DA2 may be smaller than the area of each of thesub-pixels SP1, SP2, and SP3 of the first display area DA1.

A length of the pixel PX of the second display area DA2 in a directionmay be smaller than a length of the pixel PX of the first display areaDA1 in a direction. For example, a length Y2 of the pixel PX of thesecond display area DA2 in the second direction (Y-axis direction) maybe smaller than a length Y1 of the pixel PX of the first display areaDA1 in the second direction (Y-axis direction). In an embodiment, thelength Y2 of each of the sub-pixels SP1, SP2, and SP3 of the seconddisplay area DA2 in the second direction (Y-axis direction) may besmaller than the length Y1 of each of the sub-pixels SP1, SP2, and SP3of the first display area DA1 in the second direction (Y-axisdirection).

In another embodiment, a length of the pixel PX of the second displayarea DA2 in the first direction (X-axis direction) may be smaller than alength of the pixel PX of the first display area DA1 in the firstdirection (X-axis direction). The length of each of the sub-pixels SP1,SP2, and SP3 of the second display area DA2 in the first direction(X-axis direction) may be smaller than the length of each of thesub-pixels SP1, SP2, and SP3 of the first display area DA1 in the firstdirection (X-axis direction).

When the length of the pixel PX of the second display area DA2 in adirection is smaller than the length of the pixel PX of the firstdisplay area DA1 in a direction, the transmission area TA may extend inthe other direction. For example, when the length Y2 of the pixel PX ofthe second display area DA2 in the second direction (Y-axis direction)is smaller than the length Y1 of the pixel PX of the first display areaDA1 in the second direction (Y-axis direction), the transmission area TAmay extend in the first direction (X-axis direction).

As shown in FIG. 8, the area of the transmission area TA may beincreased as the area of the pixel PX of the second display area DA2 isreduced compared to that of the pixel PX of the first display area DA1.Therefore, an amount of light incident on the optical devices 740, 750,760, and 770 arranged on the back surface of the display panel 300through the transmission areas TA may be increased. Accordingly, lightsensing of the optical devices 740, 750, 760, and 770 may be improved.

FIG. 9 is a cross-sectional view illustrating an example of a displaypanel taken along the lines I-I′ and II-II′ of FIG. 7. FIG. 9illustrates a cross-sectional view of one of the sub-pixels SP1, SP2,and SP3 of the second display area DA2 and the transmission area TA.

Each of the sub-pixels SP1, SP2, and SP3 of the first display area DA1may include at least one first thin film transistor, at least one firstcapacitor, and a plurality of light emitting elements. Referring to FIG.9, each of the sub-pixels SP1, SP2, and SP3 of the second display areaDA2 may include at least one second thin film transistor ST2, at leastone second capacitor C2, and a plurality of light emitting elements 175.Since each of the sub-pixels SP1, SP2, and SP3 of the first display areaDA1 may be substantially the same as that shown in FIG. 9 except thatthe transmission area TA is formed, a further description thereof willbe omitted.

A first substrate SUB1 may be made of an insulating material, such as apolymer resin. For example, the first substrate SUB1 may includepolyimide. Referring to FIG. 9, the first substrate SUB1 may be aflexible substrate capable of bending, folding, rolling, or the like.

A first buffer film BF1 may be disposed on the first substrate SUB1. Thefirst buffer film BF1 is a film for protecting the second thin filmtransistor ST2 and the light emitting elements 175 from moisturepenetrating through the first substrate SUB1 which may be vulnerable tomoisture permeation. In an embodiment, the first buffer film BF1 mayinclude a plurality of inorganic films alternately stacked. For example,the first buffer film BF1 may be formed as a multi-layer film in whichone or more inorganic layers of a silicon nitride layer, a siliconoxynitride layer, a silicon oxide layer, a titanium oxide layer, and analuminum oxide layer are alternately stacked.

A second active layer ACT2, a second source electrode S2, and a seconddrain electrode D2 of the second thin film transistor ST2 may bedisposed on the first buffer film BF1. In an embodiment, the secondactive layer ACT2 may include polycrystalline silicon, monocrystallinesilicon, low-temperature polycrystalline silicon, amorphous silicon, oran oxide semiconductor. The second source electrode S2 and the seconddrain electrode D2 may have conductivity by doping a siliconsemiconductor or an oxide semiconductor with ions or impurities. Thesecond active layer ACT2 may overlap a second gate electrode G2 in thethird direction (Z-axis direction) which is a thickness direction of thefirst substrate SUB1, and the second source electrode S2 and the seconddrain electrode D2 may not overlap the second gate electrode G2 in thethird direction (Z-axis direction).

A first gate insulating film 130 may be disposed on the second activelayer ACT2, the second source electrode S2, and the second drainelectrode D2. The first gate insulating film 130 may be formed of aninorganic layer, for example, a silicon nitride layer, a siliconoxynitride layer, a silicon oxide layer, a titanium oxide layer, or analuminum oxide layer.

The second gate electrode G2 of the second thin film transistor ST2 anda second capacitor electrode CAE2 of the second capacitor C2 may bedisposed on the first gate insulating film 130. The second gateelectrode G2 may overlap the second active layer ACT2 in the thirddirection (Z-axis direction). A first capacitor electrode CAE1 mayoverlap the second capacitor electrode CAE2 in the third direction(Z-axis direction). The second gate electrode G2 and the secondcapacitor electrode CAE2 may be formed as a single layer or multiplelayers including any of molybdenum (Mo), aluminum (Al), chromium (Cr),gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu),or including an alloy thereof.

A first interlayer insulating film 141 may be disposed on the secondgate electrode G2 and the second capacitor electrode CAE2. The firstinterlayer insulating film 141 may be formed of an inorganic layer, forexample, a silicon nitride layer, a silicon oxynitride layer, a siliconoxide layer, a titanium oxide layer, or an aluminum oxide layer.

The first capacitor electrode CAE1 of the second capacitor C2 may bedisposed on the first interlayer insulating film 141. Since the firstinterlayer insulating film 141 may have a predetermined dielectricconstant, a capacitor may be formed by the first capacitor electrodeCAE1, the second capacitor electrode CAE2, and the first interlayerinsulating film 141. The first capacitor electrode CAE1 may be formed asa single layer or multiple layers including any of molybdenum (Mo),aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni),neodymium (Nd), and copper (Cu), or including an alloy thereof.

A second interlayer insulating film 142 may be disposed on the firstcapacitor electrode CAE1. The second interlayer insulating film 142 maybe formed of an inorganic layer, for example, a silicon nitride layer, asilicon oxynitride layer, a silicon oxide layer, a titanium oxide layer,or an aluminum oxide layer. In an embodiment, the second interlayerinsulating film 142 may include a plurality of inorganic layers.

A first connection electrode 151 and a second connection electrode 152may be disposed on the second interlayer insulating film 142. The firstconnection electrode 151 may be connected to the second source electrodeS2 through a contact hole penetrating the gate insulating film 130, thefirst interlayer insulating film 141, and the second interlayerinsulating film 142 to expose the second source electrode S2 of thesecond thin film transistor ST2. The second connection electrode 152 maybe connected to the second drain electrode D2 through a contact holepenetrating the gate insulating film 130, the first interlayerinsulating film 141, and the second interlayer insulating film 142 toexpose the second drain electrode D2 of the second thin film transistorST2. Each of the first connection electrode 151 and the secondconnection electrode 152 may be formed as a single layer or multiplelayers including any of molybdenum (Mo), aluminum (Al), chromium (Cr),gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu),or including an alloy thereof.

A first planarization film 160 may be disposed on the first connectionelectrode 151 and the second connection electrode 152. The firstplanarization film 160 may be formed of an organic material, such as anacrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or apolyimide resin.

A first alignment electrode 171, a second alignment electrode 173, afirst inner bank 410, a second inner bank 420, and an outer bank 430 maybe disposed on the first planarization film 160.

The first inner bank 410, the second inner bank 420, and the outer bank430 may be disposed to be spaced apart from each other. The height ofthe first inner bank 410 (for example, length in the third direction(Z-axis direction)) may be smaller than the height of the outer bank430. The height of the second inner bank 420 may be smaller than theheight of the outer bank 430. The first inner bank 410, the second innerbank 420, and the outer bank 430 may be formed of an organic material,such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamideresin, or a polyimide resin.

Each of the first inner bank 410, the second inner bank 420, and theouter bank 430 may include a lower surface contacting the upper surfaceof the first planarization film 160, an upper surface facing away fromthe lower surface, and side surfaces between the upper surface and thelower surface. In an embodiment, the side surfaces of the first innerbank 410, the side surfaces of the second inner bank 420, and the sidesurfaces of the third inner bank 430 may be inclined. For example, eachof the first inner bank 410, the second inner bank 420, and the outerbank 430 may have a trapezoidal cross-sectional shape, but the shapethereof is not limited thereto.

The first electrode branch portion 171B of the first alignment electrode171 may be disposed on the first inner bank 410, and the secondelectrode branch portion 173B of the second alignment electrode 173 maybe disposed on the second inner bank 420. The first electrode branchportion 171B of the first alignment electrode 171 may be connected tothe first electrode stem portion 171S of the first alignment electrode171. The first electrode stem portion 171S of the first alignmentelectrode 171 may be connected to the first connection electrode 152 inthe first electrode contact hole CNTD. Therefore, the first alignmentelectrode 171 may be electrically connected to the second drainelectrode D2 of the second thin film transistor ST2.

The first alignment electrode 171 and the second alignment electrode 173may include a conductive material having high reflectance. For example,the first alignment electrode 171 and the second alignment electrode 173may include a metal, such as silver (Ag), copper (Cu), or aluminum (Al).Accordingly, light traveling from the light emitting element 175 to thefirst alignment electrode 171 and the second alignment electrode 173, inthe light emitted from the light emitting element 175, may be reflectedby the first alignment electrode 171 and the second alignment electrode173 and travel upward the light emitting element 175.

A first insulating film 181 may be disposed on the first alignmentelectrode 171 and the second alignment electrode 173. The firstinsulating film 181 may be disposed on the outer bank 430. The firstelectrode branch portion 171B disposed on the upper surface of the firstinner bank 410 and the second electrode branch portion 173B disposed onthe upper surface of the second inner bank 420 may be exposed withoutbeing covered by the first insulating film 181. The first insulatingfilm 181 may be formed of an inorganic layer, for example, a siliconnitride layer, a silicon oxynitride layer, a silicon oxide layer, atitanium oxide layer, or an aluminum oxide layer.

The light emitting elements 175 may be disposed on the first insulatingfilm 181 disposed between the first inner bank 410 and the second innerbank 420. One end of each of the light emitting elements 175 may bedisposed adjacent to the first inner bank 410, and the other end thereofmay be disposed adjacent to the second inner bank 420.

A second insulating film 182 may be disposed on the light emittingelements 175. The second insulating film 182 may be formed of aninorganic layer, for example, a silicon nitride layer, a siliconoxynitride layer, a silicon oxide layer, a titanium oxide layer, or analuminum oxide layer.

The first contact electrode 174 a may be in contact with the firstelectrode branch portion 171B exposed without being covered by the firstinsulating film 181, and may be in contact with one end of the lightemitting element 175. The first contact electrode 174 a may be disposedon the second insulating film 182. In order to prevent or substantiallyprevent the light emitted from the light emitting elements 175 frombeing blocked by the first contact electrode 174 a, the first contactelectrode 174 a may be made of a transparent conductive oxide (TCO),such as indium tin oxide (ITO) or indium zinc oxide (IZO), which cantransmit light.

A third insulating film 183 may be disposed on the first contactelectrode 174 a. The third insulating film 183 may be disposed to coverthe first contact electrode 174 a to electrically separate the firstcontact electrode 174 a and the second contact electrode 174 b. Thethird insulating film 183 may be formed of an inorganic layer, forexample, a silicon nitride layer, a silicon oxynitride layer, a siliconoxide layer, a titanium oxide layer, or an aluminum oxide layer.

The second contact electrode 174 b may be in contact with the secondelectrode branch portion 173B exposed without being covered by the firstinsulating film 181, and may be in contact with the other end of thelight emitting element 175. The second contact electrode 174 b may bedisposed on the second insulating film 182 and the third insulating film183. In order to prevent or substantially prevent the light emitted fromthe light emitting elements 175 from being blocked by the second contactelectrode 174 b, the second contact electrode 174 b may be made of atransparent conductive oxide (TCO), such as indium tin oxide (ITO) orindium zinc oxide (IZO), which can transmit light.

One end of each of the light emitting elements 175 may be electricallyconnected to the second drain electrode D2 of the second thin filmtransistor ST2 through the first contact electrode 174 a and the firstalignment electrode 171, and the other end thereof may be connected tothe second alignment electrode 173 through the second contact electrode174 b. Therefore, each of the light emitting elements 175 may emit lightaccording to a current flowing from one end to the other end.

An encapsulation layer TFE may be disposed on the third insulating film183 that is not covered by the second contact electrode 174 b. In anembodiment, the encapsulation layer TFE may include a first inorganicfilm TFE1, an organic film TFE2, and a second inorganic film TFE3. Thefirst inorganic film TFE1 may be disposed on the third insulating film183 that is not covered by the second contact electrode 174 b, theorganic film TFE2 may be disposed on the first inorganic film TFE1, andthe second inorganic film TFE3 may be disposed on the organic film TFE2.In an embodiment, each of the first inorganic film TFE1 and the secondinorganic film TFE3 may be formed as a multi-layer film in which one ormore inorganic layers of a silicon nitride layer, a silicon oxynitridelayer, a silicon oxide layer, a titanium oxide layer, and an aluminumoxide layer are alternately stacked. In an embodiment, the organic filmTFE2 may be formed of an acrylic resin, an epoxy resin, a phenolicresin, a polyamide resin, or a polyimide resin.

A first sensor insulating film TINS1 may be disposed on theencapsulation layer TFE. The first sensor insulating film TINS1 mayinclude at least one inorganic layer. For example, the first sensorinsulating film TINS1 may be formed as a multi-layer film in which oneor more inorganic layers of a silicon nitride layer, a siliconoxynitride layer, a silicon oxide layer, a titanium oxide layer, and analuminum oxide layer are alternately stacked.

A second sensor insulating film TINS2 may be disposed on the firstsensor insulating film TINS1. The second sensor insulating film TINS2may include at least one inorganic layer. For example, the second sensorinsulating film TINS2 may be formed as a multi-layer film in which oneor more inorganic layers of a silicon nitride layer, a siliconoxynitride layer, a silicon oxide layer, a titanium oxide layer, and analuminum oxide layer are alternately stacked.

Sensor electrodes SE may be disposed on the second sensor insulatingfilm TINS2. In an embodiment, the sensor electrodes SE may beself-capacitance type touch electrodes for sensing a user's touch. Inanother embodiment, the sensor electrodes SE may be mutual capacitancetype touch electrodes including driving electrodes and sensingelectrodes to sense a user's touch. In an embodiment, each of the sensorelectrodes SE may be formed as a single layer of molybdenum (Mo),titanium (Ti), copper (Cu), or aluminum (Al), or may be formed as alaminate structure (Ti/Al/Ti) of aluminum and titanium, a laminatestructure (ITO/Al/ITO) of aluminum and ITO, an APC alloy structure, or alaminate structure (ITO/APC/ITO) of an APC alloy and ITO.

In order to prevent or reduce the blocking of light emitted from thelight emitting element 175 by the sensor electrodes SE, the sensorelectrode SE may not overlap the light emitting element 175 in the thirddirection (Z-axis direction). The sensor electrode SE may overlap theouter bank 430 in the third direction (Z-axis direction).

A third sensor insulating film TINS3 may be disposed on the sensorelectrodes SE. The third sensor insulating film TINS3 may include atleast one of an inorganic layer and an organic layer. The inorganiclayer may be a silicon nitride layer, a silicon oxynitride layer, asilicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.The organic layer may include an acrylic resin, an epoxy resin, aphenolic resin, a polyamide resin, or a polyimide resin.

The transmission area TA may be an area in which the second thin filmtransistor ST2, the alignment electrodes 171 and 173, the contactelectrodes 174, the light emitting element 175, and the sensorelectrodes SE are not disposed to transmit light. The transmission areaTA may include a transmission hole TAH. The transmission hole TAH may bea hole that penetrates the first buffer film BF1, the gate insulatingfilm 130, the first interlayer insulating film 141, the secondinterlayer insulating film 142, the first planarization film 160, thefirst insulating film 181 and the third insulating film 182 to exposethe first substrate SUB1. The transmission hole TAH may be filled withthe encapsulating layer TFE. For example, the transmission hole TAH maybe filled with the first inorganic film TFE1 and the organic film TFE2.Thus, in the transmission area TA, the first inorganic film TFE1 and theorganic film TFE2 may be in contact with the first substrate SUB1.Further, since the transmission hole TAH of the transmission area TA isfilled with the organic film TFE2, the maximum thickness of the organicfilm TFE2 in the transmission area TA may be greater than the maximumthickness of the organic film TFE2 in an area other than thetransmission area TA.

Although it is illustrated in FIG. 9 that the transmission hole TAH is ahole that penetrates the first buffer film BF1, the gate insulating film130, the first interlayer insulating film 141, the second interlayerinsulating film 142, the first planarization film 160, the firstinsulating film 181 and the third insulating film 182 to expose thefirst substrate SUB1, the present invention is not limited thereto. Thetransmission hole TAH may be a hole that penetrates at least one of thefirst buffer film BF1, the gate insulating film 130, the firstinterlayer insulating film 141, the second interlayer insulating film142, the first planarization film 160, the first insulating film 181 andthe third insulating film 182.

When the first planarization film 160 is formed of polyimide having ahigh absorption rate of short-wavelength light, that is, blue-basedlight, in the light detected by the optical devices 740, 750, 760, and770 through the transmission areas TA, the intensity of light having ashort wavelength may be very low. Since the transmission area TAincludes the transmission hole TAH penetrating the first planarizationfilm 160 formed of polyimide, in the light incident on the opticaldevices 740, 750, 760, and 770 through the transmission area TA, lighthaving a short wavelength may be prevented or substantially preventedfrom being absorbed by at least one organic layer.

FIG. 10 is a layout view illustrating a first display area of a displaypanel according to another embodiment.

The embodiment of FIG. 10 is different from the embodiment of FIG. 5 inthat the first display area DA1 includes an organic light emitting diodeincluding a light emitting layer 272 as a light emitting element.

It is illustrated in FIG. 10 that the sensor electrodes SE are mutualcapacitance type touch electrodes including driving electrodes TE andsensing electrodes RE to detect a user's touch. For convenience ofexplanation, FIG. 10 illustrates two sensing electrodes RE adjacent inthe first direction (X-axis direction) and two driving electrodes TEadjacent in the second direction (Y-axis direction).

Referring to FIG. 10, the driving electrodes TE and the sensingelectrodes RE may be electrically separated from each other. In anembodiment, the driving electrodes TE and the sensing electrodes RE areformed on the same layer, and they may be disposed to be spaced apartfrom each other. A gap may be formed between the driving electrode TEand the sensing electrode RE.

The sensing electrodes RE may be electrically connected to each other inthe first direction (X-axis direction). The driving electrodes TE may beelectrically connected to each other in the second direction (Y-axisdirection). In order for the sensing electrodes RE and the drivingelectrodes TE to be electrically separated at their intersections, thedriving electrodes TE adjacent to each other in the second direction(Y-axis direction) may be connected through first connection portionsBE1.

The first connection portion BE1 may be formed on a different layer fromthe driving electrodes TE and the sensing electrodes RE, and may beconnected to the driving electrodes TE through first sensor contactholes TCNT1. One end of the first connection portion BE1 may beconnected to any one of the driving electrodes TE adjacent to each otherin the second direction (Y-axis direction) through the first sensorcontact holes TCNT1. The other end of the first connection portion BE1may be connected to another of the driving electrodes TE adjacent toeach other in the second direction (Y-axis direction) through the firstsensor contact holes TCNT1. The first connection portion BE1 may overlapthe sensing electrode RE in the third direction (Z-axis direction).Since the first connection portion BE1 is formed on a different layerfrom the driving electrodes TE and the sensing electrodes RE, the firstconnection portion BE1 may be electrically separated from the sensingelectrode RE despite overlapping the sensing electrode RE in the thirddirection (Z-axis direction).

In an embodiment, the first connection portions BE1 may be formed to bebent at least once. Although it is illustrated in FIG. 10 that the firstconnecting portions BE1 are bent like a clasp (“<” or “>”), the shape ofthe first connection portions BE1 is not limited thereto. Further, sincethe driving electrodes TE adjacent to each other in the second direction(Y-axis direction) are connected by the plurality of first connectionportions BE1, even if one of the first connection units BE1 isdisconnected, the driving electrodes TE adjacent to each other in thesecond direction (Y-axis direction) may be electrically connected toeach other.

Each of the driving electrodes TE and the sensing electrodes RE may havea planar shape of a mesh structure or a network structure. Since thedriving electrodes TE and the sensing electrodes RE are formed on theencapsulation layer (TFE of FIG. 11), a distance between the firstcontact electrode 174 a or the second contact electrode 174 b and thedriving electrode TE or the sensing electrode RE is short. Therefore,parasitic capacitance may be formed between the first contact electrode174 a or the second contact electrode 174 b and the driving electrode TEor the sensing electrode RE. Since the parasitic capacitance isproportional to the overlap area between the first contact electrode 174a or the second contact electrode 174 b and the driving electrode TE orthe sensing electrode RE, in order to reduce parasitic capacitance, inan embodiment, each of the driving electrodes TE and the sensingelectrodes RE has a planar shape of a mesh structure or a networkstructure.

The first display area DA1 may include light emitting areas EA. Each ofthe light emitting areas EA includes a first light emitting area EA1emitting a first light, a second light emitting area EA2 emitting asecond light, a third light emitting area EA3 emitting a third light,and a fourth light emitting area EA4 emitting a fourth light. In anembodiment, the first light emitting area EA1, the second light emittingarea EA2, the third light emitting area EA3, and the fourth lightemitting area EA4 may emit light of different colors from each other. Inanother embodiment, two of the first light emitting area EA1, the secondlight emitting area EA2, the third light emitting area EA3, and thefourth light emitting area EA4 may emit light of a same color. Forexample, the first light emitting area EA1 may emit red light, thesecond light emitting area EA2 and the fourth light emitting area EA4may emit green light, and the third light emitting area EA3 may emitblue light.

It is illustrated in FIG. 10 that each of the first light emitting areaEA1, the second light emitting area EA2, the third light emitting areaEA3, and the fourth light emitting area EA4 has a rectangular planarshape such as a rhombus, but the present invention is not limitedthereto. For example, the first light emitting area EA1, the secondlight emitting area EA2, the third light emitting area EA3, and thefourth light emitting area EA4 may have a polygonal, circular, orelliptical plane shape other than a rectangular shape. Further, it isillustrated in FIG. 10 that among the first light emitting area EA1, thesecond light emitting area EA2, the third light emitting area EA3, andthe fourth light emitting area EA4, the third light emitting area EA3has the largest size, the first light emitting area EA1 has the secondlargest size, and the second light emitting area EA2 and the fourthlight emitting area EA4 have the smallest size, but the presentinvention is not limited thereto.

In an embodiment, since the driving electrodes TE, the sensingelectrodes RE, and the first connection portions BE1 are formed in amesh structure or a network structure on a plane, the light emittingareas EA may not overlap the driving electrodes TE, the sensingelectrodes RE, and the first connection portions BE1 in the thirddirection (Z-axis direction). Therefore, the light emitted from thelight emitting areas EA is blocked by the driving electrodes TE, thesensing electrodes RE, and the first connection portions BE1, therebypreventing or decreasing the reduction in luminance of light.

FIG. 11 is a cross-sectional view illustrating an example of a displaypanel taken along the line III-Ill′ of FIG. 10.

FIG. 11 illustrates a cross-sectional view of a sub-pixel SPcorresponding to the third light emitting area EA3 of the first displayarea DA1.

Referring to FIG. 11, the sub-pixel SP of the first display area DA1 mayinclude at least one first thin film transistor ST1, at least one firstcapacitor C1, and an organic light emitting diode OLE.

Since the first thin film transistor ST1 and the first capacitor C1 maybe substantially the same as those of the second thin film transistorST2 and the second capacitor C2 described with reference to FIG. 9,further descriptions thereof will be omitted. Further, since the firstsubstrate SUB1, the first buffer film BF1, the gate insulating film 130,the first interlayer insulating film 141, the second interlayerinsulating film 142, and the first planarization film 160 may also besubstantially the same as those described with reference to FIG. 9,further descriptions thereof will be omitted.

The organic light emitting diode OLE and a bank 180 may be disposed onthe first planarization film 160. The organic light emitting diode OLEincludes a first light emitting electrode 271, a light emitting layer272, and a second light emitting electrode 273.

The first light emitting electrode 271 may be formed on the firstplanarization film 160. The first light emitting electrode 271 may beconnected to the second connection electrode 152 through a contact holeCNTD that penetrates the first planarization film 160 to expose thesecond connection electrode 152.

In a top emission structure in which light is emitted in the directionof the second light emitting electrode 273 based on the light emittinglayer 272, the first light emitting electrode 271 may be formed of ametal material having high reflectance, such as a laminate structure(Ti/Al/Ti) of aluminum and titanium, a laminate structure (ITO/Al/ITO)of aluminum and ITO, an APC alloy, or a laminate structure (ITO/APC/ITO)of an APC alloy and ITO. The APC alloy is an alloy of silver (Ag),palladium (Pd), and copper (Cu).

The bank 180 may be disposed on the first planarization film 160. Thebank 180 may be formed to partition the first light emitting electrode271 to define the light emitting area EA. The bank 180 may be formed tocover the edge of the first light emitting electrode 271. The bank 180may be formed of an organic material, such as an acrylic resin, an epoxyresin, a phenolic resin, a polyamide resin, or a polyimide resin.

The first light emitting area EA1, the second light emitting area EA2,the third light emitting area EA3, and the fourth light emitting areaEA4 are referred to as areas in which the first light emitting electrode271, the light emitting layer 272, and the second light emittingelectrode 273 are sequentially stacked, and, thus, holes from the firstlight emitting electrode 271 and electrons from the second lightemitting electrode 273 are recombined with each other in the lightemitting layer 272 to emit light.

The light emitting layer 272 is formed on the first light emittingelectrode 271 and the bank 180. The light emitting layer 272 may includean organic material to emit light of a color (e.g., a predeterminedcolor). For example, the light emitting layer 272 may include a holetransporting layer, an organic material layer, and an electrontransporting layer.

The second light emitting electrode 273 may be formed on the lightemitting layer 272. The second light emitting electrode 273 may beformed to cover the light emitting layer 272. In an embodiment, thesecond light emitting electrode 273 may be a common layer formed incommon in all light emitting areas EA. A capping layer may be formed onthe second light emitting electrode 273.

In the top emission structure, the second light emitting electrode 273may be formed of a transparent conductive oxide (TCO), such as indiumtin oxide (ITO) or indium zinc oxide (IZO), that can transmit light, ormay be formed of a semi-transmissive conductive material, such asmagnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver(Ag). In an embodiment, when the second light emitting electrode 273 isformed of a semi-transmissive metal material, light emission efficiencymay be increased by microcavities.

An encapsulation layer TFE may be disposed on the second light emittingelectrode 273, and a first connection portion BE1, driving electrodesTE, and sensing electrodes RE may be disposed on the encapsulation layerTFE.

Since the encapsulation layer TFE may be substantially the same as thatdescribed with reference to FIG. 9, a further description thereof willbe omitted. The first connection portion BE1 may be disposed on thefirst sensor insulating film TINS1, and may be covered by the secondsensor insulating film TINS2. The first connection portion BE1 may notoverlap the first light emitting area EA1, the second light emittingarea EA2, the third light emitting area EA3, and the fourth lightemitting area EA4 in the third direction (Z-axis direction). The firstconnection portion BE1 may overlap the bank 180 in the third direction(Z-axis direction). In an embodiment, the first connection portion BE1may be formed as a single layer of molybdenum (Mo), titanium (Ti),copper (Cu), or aluminum (Al), or may be formed of a laminate structure(Ti/Al/Ti) of aluminum and titanium, a laminate structure (ITO/Al/ITO)of aluminum and ITO, an APC alloy, or a laminate structure (ITO/APC/ITO)of an APC alloy and ITO.

The sensing electrode RE and the driving electrode TE may be disposed onthe second sensor insulating film TINS2, and may be covered by the thirdsensor insulating film TINS3. The sensing electrode RE and the drivingelectrode TE may not overlap the first light emitting area EA1, thesecond light emitting area EA2, the third light emitting area EA3, andthe fourth light emitting area EA4 in the third direction (Z-axisdirection). The sensing electrode RE and the driving electrode TE mayoverlap the bank 180 in the third direction (Z-axis direction). Thedriving electrode TE may be connected to the first connection portionBEI through the first sensor contact hole TCNT1 penetrating the secondsensor insulating film TINS2. In an embodiment, the sensing electrode REand the driving electrode TE may be formed as a single layer ofmolybdenum (Mo), titanium (Ti), copper (Cu), or aluminum (Al), or may beformed of a laminate structure (Ti/Al/Ti) of aluminum and titanium, alaminate structure (ITO/Al/ITO) of aluminum and ITO, an APC alloy, or alaminate structure (ITO/APC/ITO) of an APC alloy and ITO.

FIG. 12 is a cross-sectional view illustrating another example of adisplay panel taken along the lines I-I′ and II-II′ of FIG. 7.

The embodiment of FIG. 12 is different from the embodiment of FIG. 9 inthat, in the second display area DA2, the first sensor insulating filmTINS1 and the second sensor insulating film TINS2 are disposed on thefirst planarization film 160, and the first alignment electrode 171, thesecond alignment electrode 173, the first inner bank 410, the secondinner bank 420, and the outer bank 430 are disposed on the second sensorinsulating film TINS2. In FIG. 12, differences from the embodiment ofFIG. 9 will be mainly described.

Referring to FIG. 12, the first alignment electrode 171 and the secondalignment electrode 173 are disposed on the second sensor insulatingfilm TINS2. That is, the first alignment electrode 171 and the secondalignment electrode 173 may be disposed on a same layer as the sensingelectrodes RE and the driving electrodes TE. In an embodiment, the firstalignment electrode 171 and the second alignment electrode 173 may bemade of a same material as the sensing electrodes RE and the drivingelectrodes TE.

The first electrode stem portion 171S of the first alignment electrode171 may be connected to the second connection electrode 152 through thefirst electrode contact hole CNTD penetrating the planarization film160, the first sensor insulating film TINS1, and the second sensorinsulating film TINS2. Further, the transmission hole TAH may penetratethe first sensor insulating film TINS1 and the second sensor insulatingfilm TINS2.

As shown in FIG. 12, when the first alignment electrode 171 and thesecond alignment electrode 173 are disposed on the same layer as thesensing electrodes RE and the driving electrodes TE, and the sensingelectrodes RE and the driving electrodes TE are made of the samematerial, the first alignment electrode 171, the second alignmentelectrode 173, the sensing electrodes RE, and the driving electrodes TEmay be formed by one mask process. Therefore, any one of the maskprocess for forming the first alignment electrode 171 and the secondalignment electrode 173 and the mask process for forming the sensingelectrodes RE and the driving electrodes TE may be omitted, such thatmanufacturing costs may be reduced.

FIG. 13 is a layout view illustrating a first display area of a displaypanel according to another embodiment.

The embodiment of FIG. 13 is different from the embodiment of FIG. 10 inthat each of the sensing electrodes RE and the driving electrodes TE hasa rectangular planar structure rather than a mesh structure or a networkstructure. In FIG. 13, differences from the embodiment of FIG. 10 willbe mainly described.

Referring to FIG. 13, since the sensing electrodes RE and the drivingelectrodes TE have a rectangular planar structure, they may overlap thelight emitting areas EA in the third direction (Z-axis direction). In anembodiment, the sensing electrodes RE and the driving electrodes TE maybe formed of a transparent conductive oxide (TCO), such as indium tinoxide (ITO) or indium zinc oxide (IZO), which can transmit light. Thus,even if the sensing electrodes RE and the driving electrodes TE overlapthe light emitting areas EA in the third direction (Z-axis direction),the light emitted from the light emitting areas EA may not be blocked bythe sensing electrodes RE and the driving electrodes TE.

FIG. 14 is a layout view illustrating a second display area of a displaypanel according to another embodiment.

The embodiment of FIG. 14 is different from the embodiment of FIG. 7 inthat the sensor electrode SE crosses the first alignment electrodes 171and the second alignment electrodes 173 in the second display area DA2.In FIG. 14, differences from the embodiment of FIG. 7 will be mainlydescribed.

Referring to FIG. 14, the sensor electrode SE may be disposed apart fromthe first contact electrodes 174 a and the second contact electrodes 174b. The sensor electrode SE may include a first sub-sensor electrodeSSE1, a second sub-sensor electrode SSE2, and sensor connectionelectrodes SBE.

The first sub-sensor electrode SSE1 may extend in the first direction(X-axis direction). The first sub-sensor electrode SSE1 may be disposedto cross the sub-pixels SP1, SP2, and SP3 of the pixel PX. The firstsub-sensor electrode SSE1 may intersect the first electrode branchportions 171B of the first alignment electrodes 171 of the sub-pixelsSP1, SP2, and SP3 of the pixel PX.

The second sub-sensor electrode SSE2 may extend in the first direction(X-axis direction). The second sub-sensor electrode SSE2 may be disposedto cross the sub-pixels SP1, SP2, and SP3 of the pixel PX. The secondsub-sensor electrode SSE2 may intersect the second electrode branchportions 173B of the second alignment electrodes 173 of the sub-pixelsSP1, SP2, and SP3 of the pixel PX.

Sensor connection electrodes SBE may extend in the second direction(Y-axis direction). Each of the sensor connection electrodes SBE may bedisposed between the first sub-sensor electrode SSE1 and the secondsub-sensor electrode SSE2 to connect the first sub-sensor electrode SSE1and the second sub-sensor electrode SSE2. One end of each of the sensorconnection electrodes SBE may be connected to the first sub-sensorelectrode SSE1, and the other end thereof may be connected to the secondsub-sensor electrode SSE2.

The sensor connection electrodes SBE may be disposed at boundaries amongsub-pixels SP1, SP2, and SP3 of the pixel PX. The sensor connectionelectrodes SBE may be disposed at a boundary between the first sub-pixelSP1 and the second sub-pixel SP2, and a boundary between the secondsub-pixel SP2 and the third sub-pixel SP3. Although FIG. 14 illustratestwo sensor connection electrodes SBE, the number of sensor connectionelectrodes SBE is not limited thereto. The number of sensor connectionelectrodes SBE may be one or more.

FIG. 15 is a cross-sectional view illustrating another example of adisplay panel taken along the line IV-IV′ of FIG. 13.

The embodiment of FIG. 15 is different from the embodiment of FIG. 11 inthat a display panel 300 further includes a filling layer FL, a secondsubstrate SUB2, a second buffer film BF2, a second gate insulating film230, a third interlayer insulating film 241, a fourth interlayerinsulating film 242, and a second planarization film 260, and the firstconnection portion BE1, the sensing electrodes RE, and the drivingelectrodes TE are disposed on the second planarization film 260. In FIG.15, differences from the embodiment of FIG. 11 will be mainly described.

Referring to FIG. 15, the sub-pixels SP of the first display area DA1may be disposed on the first substrate SUB1, and the sub-pixels SP1,SP2, and SP3 of the second display area DA2 and the sensor electrodes SEmay be disposed on the second substrate SUB2.

The second substrate SUB2 may be disposed over the second light emittingelectrode 273. The second substrate SUB2 may be made of an insulatingmaterial, such as a polymer resin. For example, the second substrateSUB2 may include polyimide. In an embodiment, the second substrate SUB2may be a flexible substrate capable of bending, folding, rolling, or thelike.

The filling layer FL may be disposed between the second light emittingelectrode 273 and the second substrate SUB2. In an embodiment, thefilling layer FL may be an epoxy filling film or a silicon filling film.In another embodiment, the filling layer FL may be empty in a vacuum.

The second buffer film BF2 may be disposed on the second substrate SUB2.The second buffer film BF2 is a film for protecting the second thin filmtransistor ST2 and the light emitting elements 175 from moisturepenetrating through the second substrate SUB2 which is vulnerable tomoisture permeation. In an embodiment, the second buffer film BF2 mayinclude a plurality of inorganic films alternately stacked. For example,the second buffer film BF2 may be formed as a multi-layer film in whichone or more inorganic layers of a silicon nitride layer, a siliconoxynitride layer, a silicon oxide layer, a titanium oxide layer, and analuminum oxide layer are alternately stacked.

The second thin film transistors ST2 of the second display area DA2 maybe disposed on the second buffer film BF2. Since the second thin filmtransistors ST2 are not disposed in the first display area DA1, thesecond gate insulating film 230, the third interlayer insulating film241, the fourth interlayer insulating film 242, and the secondplanarization film 260 may be sequentially stacked on the second bufferfilm BF2. Since the second gate insulating film 230, the thirdinterlayer insulating film 241, the fourth interlayer insulating film242, and the second planarization film 260 may be substantially the sameas the first gate insulating film 130, the first interlayer insulatingfilm 141, the second interlayer insulating film 142, and the firstplanarization film 160 shown in FIGS. 9, 11, and 12, furtherdescriptions thereof will be omitted.

A first sensor insulating film TINS1 may be disposed on the secondplanarization film 260. Since the first sensor insulating film TINS1 maybe substantially the same as that described with reference to FIG. 9, afurther description thereof will be omitted.

A first connection portion BE1 may be disposed on the first sensorinsulating film TINS1. Since the first connection portion BE1 may besubstantially the same as that described with reference to FIG. 11, afurther description thereof will be omitted.

The sensing electrode RE and the driving electrode TE may be disposed onthe second sensor insulating film TINS2, and may be covered by the thirdsensor insulating film TINS3. The sensing electrode RE and the drivingelectrode TE may overlap the first light emitting area EA1, the secondlight emitting area EA2, the third light emitting area EA3, and thefourth light emitting area EA4 in the third direction (Z-axisdirection). The sensing electrode RE and the driving electrode TE mayoverlap the bank 180 in the third direction (Z-axis direction). Thedriving electrode TE may be connected to the first connection portionBE1 through the first sensor contact hole TCNT1 penetrating the secondsensor insulating film TINS2. In an embodiment, the sensing electrode REand the driving electrode TE may be formed of a transparent conductiveoxide (TCO), such as indium tin oxide (ITO) and indium zinc oxide (IZO),that can transmit light. Thus, even when the sensing electrodes RE andthe driving electrodes TE overlap the light emitting areas EA in thethird direction (Z-axis direction), the light emitted from the lightemitting areas EA may not be blocked by the sensing electrodes RE andthe driving electrodes TE.

FIG. 16 is a cross-sectional view illustrating an example of a displaypanel taken along the lines V-V′ and VI-VI′ of FIG. 14.

The embodiment of FIG. 16 is different from the embodiment of FIG. 12 inthat a filling layer FL, a second substrate SUB2, a second buffer filmBF2, a second gate insulating film 230, a third interlayer insulatingfilm 241, a fourth interlayer insulating film 242, and a secondplanarization film 260 are further provided, and the first sub-sensorelectrode SSE1 of the sensor electrode SE is disposed on the thirdinsulating film 183. In FIG. 16, differences from the embodiment of FIG.12 will be mainly described.

Referring to FIG. 16, the sub-pixels SP of the first display area DA1may be disposed on the first substrate SUB1, and the sub-pixels SP1,SP2, and SP3 of the second display area DA2 and the sensor electrodes SEmay be disposed on the second substrate SUB2.

Since the filling layer FL, the second substrate SUB2, the second bufferfilm BF2, the second gate insulating film 230, the third interlayerinsulating film 241, the fourth interlayer insulating film 242, and thesecond planarization film 260 may be substantially the same as thosedescribed with reference to FIG. 15, further descriptions thereof willbe omitted.

A second active layer ACT2, a second source electrode S2, and a seconddrain electrode D2 of the second thin film transistor ST2 may bedisposed on the second buffer film BF2. The second gate insulating film230 may be disposed on the second active layer ACT2, the second sourceelectrode S2, and the second drain electrode D2.

A second gate electrode G2 of the second thin film transistor TFT2 and asecond capacitor electrode CAE2 of the second capacitor C2 may bedisposed on the second gate insulating film 230. The third interlayerinsulating film 241 may be disposed on the second gate electrode G2 andthe second capacitor electrode CAE2.

A first capacitor electrode CAE1 of the second capacitor C2 may bedisposed on the third interlayer insulating film 241. The fourthinterlayer insulating film 242 may be disposed on the first capacitorelectrode CAE1.

A third connection electrode 251 and a fourth connection electrode 252may be disposed on the third interlayer insulating film 242. The thirdconnection electrode 251 may be connected to the second source electrodeS2 through a contact hole penetrating the second gate insulating film230, the third interlayer insulating film 241, and the fourth interlayerinsulating film 242 to expose the second source electrode S2 of thesecond thin film transistor ST2. The fourth connection electrode 252 maybe connected to the second drain electrode D2 through a contact holepenetrating the second gate insulating film 230, the third interlayerinsulating film 241, and the fourth interlayer insulating film 242 toexpose the second drain electrode D2 of the second thin film transistorST2. The second planarization film 260 may be disposed on the thirdconnection electrode 251 and the fourth connection electrode 252. In anembodiment, each of the third connection electrode 251 and the fourthconnection electrode 252 may be formed of a single layer or multiplelayer including any of molybdenum (Mo), aluminum (Al), chromium (Cr),gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu)or including an alloy thereof.

The first sub-sensor electrode SSE1 of the sensor electrode SE may bedisposed on the third insulating film 183, and may be covered by thefirst inorganic film TFE1. That is, the first sub-sensor electrode SSE1of the sensor electrode SE may be disposed on a same layer as the secondcontact electrode 174 b. The first sub-sensor electrode SSE1 of thesensor electrode SE may be made of a same material as the second contactelectrode 174 b.

Further, the second sub-sensor electrode SSE2 of the sensor electrode SEand the sensor connection electrodes SBE may be disposed on the thirdinsulating film 183, and may be covered by the first inorganic filmTFE1. That is, the second sub-sensor electrode SSE2 of the sensorelectrode SE and the sensor connection electrodes SBE may be disposed ona same layer as the second contact electrode 174 b. The secondsub-sensor electrode SSE2 of the sensor electrode SE and the sensorconnection electrodes SBE may be made of a same material as the secondcontact electrode 174 b.

As shown in FIG. 16, when the sensor electrode SE is disposed on thesame layer as the second contact electrode 174 b and is made of the samematerial as the second contact electrode 174 b, the sensor electrode SEand the second contact electrode 174 b may be formed by one maskprocess. Therefore, any one of the mask process for forming the sensorelectrode SE and the mask process for forming the second contactelectrode 174 b may be omitted, thereby reducing a manufacturing cost.

FIG. 17 is a cross-sectional view illustrating another example of adisplay panel taken along the lines V-V and VI-VI′ of FIG. 14.

With respect to FIG. 17, descriptions of the first substrate SUB1, thefirst buffer film BF1, the first gate insulating film 130, the firstinterlayer insulating film 141, the second interlayer insulating film142, the first planarization film 160, the bank 180, and the fillinglayer FL are omitted to avoid redundant descriptions thereof.

The embodiment of FIG. 17 is different from the embodiment of FIG. 16 inthat a light transmitting layer LTL, a wavelength conversion layer QDL,a first color filter layer CFL1, a second color filter layer CFL2, afirst light blocking layer BM1, and a second light blocking layer BM2are disposed on the encapsulation layer TFE. In FIG. 17, differencesfrom the embodiment of FIG. 16 will be mainly described.

Referring to FIG. 17, the wavelength conversion layer QDL, the lighttransmitting layer LTL, and the first light blocking layer BM1 may bedisposed on the encapsulation layer TFE.

The wavelength conversion layer QDL may overlap the first sub-pixel SP1and the second sub-pixel SP2. The wavelength conversion layer QDL mayconvert light emitted from the light emitting elements 175 of the firstsub-pixel SP1 or the second sub-pixel SP2 into light of a differentcolor. For example, the wavelength conversion layer QDL overlapping thefirst sub-pixel SP1 may convert third light emitted from the lightemitting elements 175 of the first sub-pixel SP1 into first light. Thewavelength conversion layer QDL overlapping the second sub-pixel SP2 mayconvert third light emitted from the light emitting elements 175 of thesecond sub-pixel SP2 into second light. In an embodiment, the firstlight may be red light having a center wavelength band of 620 nm to 752nm, the second light may be green light having a center wavelength bandof 495 nm to 570 nm, and the third light may be blue light having acenter wavelength band of 450 nm to 495 nm.

In an embodiment, the wavelength conversion layer QDL may include a baseresin, a wavelength shifter, and a scatterer. The base resin may includea material having high light transmittance. For example, the base resinmay include an organic material, such as an epoxy resin, an acrylicresin, a cardo resin, or an imide resin.

The wavelength shifter may convert or shift the wavelength range of thethird light having a short wavelength. In an embodiment, the wavelengthshifter may be a quantum dot, a quantum rod, or a phosphor. In anembodiment, when the wavelength shifter is a quantum dot, the wavelengthshifter may have a specific band gap according to the composition andsize of a semiconductor nanocrystalline material. Therefore, thewavelength shifter may absorb incident light and emit light having anintrinsic wavelength. In an embodiment, the wavelength shifter may havea core-shell structure including a core including nanocrystals and ashell surrounding the core.

The scatterer may have a different refractive index from the base resinand may form an optical interface together with the base resin. Forexample, the scatterer may be a light scattering particle. For example,the scatterer may be a metal oxide particle, such as a titanium oxide(TiO₂) particle, a silicon oxide (SiO₂) particle, a zirconium oxide(ZrO₂) particle, an aluminum oxide (Al₂O₃) particle, an indium oxide(In₂O₃) particle, a zinc oxide (ZnO) particle, or a tin oxide (SnO₂)particle. In another embodiment, the scatterer may be an organicparticle, such as an acrylic resin particle or a urethane resinparticle.

The scatterer may scatter incident light in a random direction withoutsubstantially converting the wavelength of light passing through thewavelength conversion layer QDL. Thus, the length of a path of lightpassing through the wavelength conversion layer QDL may be increased,such that the color conversion efficiency by the wavelength shifter maybe increased.

The light transmitting layer LTL may overlap the third sub-pixel SP3.The light transmitting layer LTL may pass the third light emitted fromthe light emitting elements 175 of the third sub-pixel SP3 as is. Thelight transmitting layer LTL may include a material having high lighttransmittance. For example, the light transmitting layer LTL may includean organic material, such as an epoxy resin, an acrylic resin, a cardoresin, or an imide resin.

The wavelength conversion layer QDL and the light transmitting layer LTLmay be disposed to be spaced apart from each other. A first cappinglayer CPL1 may be disposed on the wavelength conversion layer QDL andthe light transmitting layer LTL. The first capping layer CPL1 preventor substantially prevents moisture or oxygen from permeating into thewavelength conversion layer QDL and the light transmitting layer LTLfrom the outside. The first capping layer CPL1 may be formed of aninorganic material, for example, silicon nitride, aluminum nitride,zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride,silicon oxide, aluminum oxide, or titanium oxide.

A first light blocking layer BM1 may be disposed in a space between thewavelength conversion layer QDL and the light transmitting layer LTL.The first light blocking layer BM1 may be disposed on the first cappinglayer CPL1. The first light blocking layer BM1 may overlap the outerbank 430 in the third direction (Z-axis direction). In an embodiment,the first light blocking layer BM1 may include an inorganic blackpigment, such as carbon black or an organic black pigment that can blocklight without transmitting light, or may include an opaque metalmaterial.

A first color filter layer CFL1 may be disposed on the wavelengthconversion layer QDL, and a second color filter layer CFL2 may bedisposed on the light transmitting layer LTL. For convenience ofexplanation, it is illustrated in FIG. 17 that the first color filterlayer CFL1 passing the first light overlaps the first sub-pixel SP1, andthe second color filter layer CFL2 passing the third light overlaps thethird sub-pixel SP3. In this case, a third color filter layer (notshown) passing the second light may overlap the second sub-pixel SP2.

A part of the third light emitted from the light emitting elements 175of the first sub-pixel SP1 may not be converted into the first light bythe wavelength shifter of the wavelength conversion layer QDLoverlapping the first sub-pixel SP1. The third light that is incident onthe first color filter layer CFL1 without being converted by thewavelength conversion layer QDL may not pass through the first colorfilter layer CFL1. In contrast, the first light converted by thewavelength conversion layer QDL may pass through the first color filterlayer CFL1.

A part of the third light emitted from the light emitting elements 175of the second sub-pixel SP2 may not be converted into the second lightby the wavelength shifter of the wavelength conversion layer QDLoverlapping the second sub-pixel SP2. The second light that is incidenton the third color filter layer (not shown) without being converted bythe wavelength conversion layer QDL may not pass through the third colorfilter layer (not shown). In contrast, the second light converted by thewavelength conversion layer QDL may pass through the third color filterlayer (not shown).

The third light emitted from the light emitting elements 175 of thethird sub-pixel SP3 may pass through the light transmitting layer LTLand the second color filter layer CFL2 overlapping the third sub-pixelSP3.

The first color filter layer CFL1, the second color filter layer CFL2,and the third color filter layer (not shown) may be disposed to bespaced apart from each other. A second capping layer CPL2 may bedisposed on the first color filter layer CFL1, the second color filterlayer CFL2, and the third color filter layer (not shown). The secondcapping layer CPL2 prevents or substantially prevents moisture or oxygenfrom permeating into the wavelength conversion layer QDL and the lighttransmitting layer LTL from the outside. The second capping layer CPL2may be formed of an inorganic material, for example, silicon nitride,aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride,tantalum nitride, silicon oxide, aluminum oxide, or titanium oxide.

A second light blocking layer BM2 may be disposed in a space between thefirst color filter layer CFL1, the second color filter layer CFL2, andthe third color filter layer (not shown). The second light blockinglayer BM2 may be disposed on the second capping layer CPL2. The secondlight blocking layer BM2 may overlap the outer bank 430 in the thirddirection (Z-axis direction). In an embodiment, the second lightblocking layer BM2 may include an inorganic black pigment, such ascarbon black or an organic black pigment that can block light withouttransmitting light, or may include an opaque metal material.

In an embodiment, in order to increase the light transmittance of thetransmission area TA, the light transmitting layer LTL, the wavelengthconversion layer QDL, the first color filter layer CFL1, the secondcolor filter layer CFL2, the first light blocking layer BM1, and thesecond light blocking layer BM2 may not be disposed in the transmissionarea TA. The first capping layer CPL1 and the second capping layer CPL2may be disposed on the transmission area TA, but the present inventionis not limited thereto. The first capping layer CPL1 and the secondcapping layer CPL2 may also not be disposed in the transmission area TA.

FIG. 18 is a cross-sectional view illustrating an example of a displaypanel taken along the line IV-IV′ of FIG. 13.

The embodiment of FIG. 18 is different from the embodiment of FIG. 15 inthat a second substrate SUB2, a second buffer film BF2, a second gateinsulating film 230, a third interlayer insulating film 241, a fourthinterlayer insulating film 242, a second planarization film 260, a firstsensor insulating film TINS1, a first connection portion BE1, a secondsensor insulating film TINS2, a sensing electrode RE, a drivingelectrode TE, and a third sensor insulating film TINS3 are stacked fromtop to bottom. Therefore, a further description of the embodiment ofFIG. 18 will be omitted.

FIG. 19 is a cross-sectional view illustrating another example of adisplay panel taken along the lines V-V and VI-VI′ of FIG. 14.

The embodiment of FIG. 19 is different from the embodiment of FIG. 15 inthat a second substrate SUB2, a second buffer film BF2, a second gateinsulating film 230, a third interlayer insulating film 241, a fourthinterlayer insulating film 242, a second planarization film 260, a firstsensor Insulating film TINS1, a second sensor insulating film TINS2, afirst inner bank 410, a second inner bank 420, an outer bank 430, afirst alignment electrode 171, a second alignment electrode 173, a firstinsulating film 181, light emitting elements 175, a second insulatingfilm 182, a first contact electrode 174 a, a third insulating film 183,a second contact electrode 174 b, a sensor electrode SE, and anencapsulation layer TFE are stacked from top to bottom. Therefore, afurther description of the embodiment of FIG. 19 will be omitted.

FIGS. 20 to 22 are perspective views of a display device according toanother embodiment.

Although it is illustrated in FIGS. 20 to 22 that the display device 10is a foldable display device folded in the first direction (X-axisdirection), the present invention is not limited thereto. The displaydevice 10 may be folded in the second direction (Y-axis direction).

Referring to FIGS. 20 to 22, the display device 10 may maintain both afolded state and an unfolded state. The display device 10 may be foldedin an in-folding manner in which the front surface is disposed inward asshown in FIG. 21. When the display device 10 is bent or folded in anin-folding manner, the front surfaces of the display devices 10 may bedisposed to face each other. In an embodiment, the display device 10 maybe folded in an out-folding manner in which the front surface isdisposed outward as shown in FIG. 22. When the display device 10 is bentor folded in an out-folding manner, the back surfaces of the displaydevice 10 may be disposed to face each other.

A first non-folding area NFA1 may be disposed at one side of a foldingarea FDA, for example, at the right side of the folding area FDA. Asecond non-folding area NFA2 may be disposed at the other side of thefolding area FDA, for example, at the left side of the folding area FDA.

A first folding line FOL1 and a second folding line FOL2 may extend inthe second direction (Y-axis direction), and the display device 10 maybe folded in the first direction (X-axis direction). Thus, since alength of the display device 10 in the first direction (X-axisdirection) may be reduced to approximately half, a user may convenientlycarry the display device 10.

However, the extending direction of the first folding line FOL1 and theextending direction of the second folding line FOL2 are not limited tothe second direction (Y-axis direction). For example, the first foldingline FOL1 and the second folding line FOL2 may extend in the firstdirection (X-axis direction), and the display device 10 may be folded inthe second direction (Y-axis direction). In this case, a length of thedisplay device 10 in the second direction (Y-axis direction) may bereduced to approximately half. In an embodiment, the first folding lineFOL1 and the second folding line FOL2 may extend in a diagonal directionof the display device 10 between the first direction (X-axis direction)and the second direction (Y-axis direction). In this case, the displaydevice 10 may be folded in a triangular plane shape.

When the first folding line FOL1 and the second folding line FOL2 extendin the second direction (Y-axis direction), the length of the foldingarea FDA in the first direction (X-axis direction) may be shorter thanthe length of the folding area FDA in the second direction (Y-axisdirection). Further, the length of the first non-folding area NFA1 inthe first direction (X-axis direction) may be longer than the length ofthe folding area FDA in the first direction (X-axis direction). Thelength of the second non-folding area NFA2 in the first direction(X-axis direction) may be longer than the length of the folding area FDAin the first direction (X-axis direction).

In an embodiment, the display device 10 may include a first display areaDA1, a second display area DA2, a third display area DA3, a firstnon-display area NDA1, and a second non-display area NDA2. A number ofsub-pixels SP1, SP2, and SP3 per unit area in the second display areaDA2 may be less than a number of sub-pixels SP1, SP2, SP3 per unit areain the first display area DA1. The number of sub-pixels SP1, SP2, andSP3 per unit area in the second display area DA2 may be less than anumber of sub-pixels SP1, SP2, SP3 per unit area in the third displayarea DA3.

The first display area DA1, the second display area DA2, and the firstnon-display area NDA1 may be disposed on the front surface of thedisplay device 10. The first display area DA1 may overlap the foldingarea FDA, the first non-folding area NFA1, and the second non-foldingarea NFA2. Therefore, when the display device 10 is unfolded, an imagemay be displayed in the folding area FDA, the first non-folding areaNFA1, and the second non-folding area NFA2 of the display device 10.

Although it is illustrated that the second display area DA2 is disposedin the first non-folding area NFA1, the present invention is not limitedthereto. The second display area DA2 may be disposed in the secondnon-folding area NFA2.

The third display area DA3 and the second non-display area NDA2 may bedisposed on a back surface of the display device 10. The third displayarea DA3 may overlap the second non-folding area NFA2. Therefore, whenthe display device 10 is folded in an in-folding manner as shown in FIG.21, an image may be displayed in the third display area DA3 disposed onthe back surface of the second non-folding area NFA2 of the displaydevice 10. When the display device 10 is folded in an out-folding manneras shown in FIG. 22, an image may be displayed in the first display areaDA1 and the second display area DA2 disposed on the front surface of thefirst non-folding area NFA1 of the display device 10.

FIGS. 23 and 24 are perspective views of a display device according toanother embodiment.

Referring to FIGS. 23 and 24, the display device 10 may maintain both afolded state and an unfolded state. In an embodiment, the display device10 may be folded in a Z-folding manner as shown in FIG. 24. For example,the front surface of the first non-folding area NFA1 of the displaydevice 10 and the front surface of the second non-folding area NFA2 ofthe display device 10 may be bent or folded in an in-folding manner soas to face each other. The back surface of the first non-folding areaNFA1 of the display device 10 and the back surface of a thirdnon-folding area NFA3 of the display device 10 may be bent or folded inan out-folding manner so as to face each other.

The first non-folding area NFA1 may be disposed at one side of a firstfolding area FDA1, for example, at the right side of the first foldingarea FDA1. The second non-folding area NFA2 may be disposed at the otherside of the first folding area FDA1, for example, at the left side ofthe first folding area FDA1. The third non-folding area NFA3 may bedisposed at one side of a second folding area FDA2, for example, at theright side of the second folding area FDA2. The first non-folding areaNFA1 may be disposed at the other side of the second folding area FDA2,for example, at the left side of the second folding area FDA2.

The first folding line FOL1, the second folding line FOL2, a thirdfolding line FOL3, and a fourth folding line FOL4 may extend in thesecond direction (Y-axis direction), and the display device 10 may befolded in the first direction (X-axis direction). Thus, a length of thedisplay device 10 in the first direction (X-axis direction) may bereduced to approximately one third, such that it may be convenient for auser to carry the display device 10.

When the first folding line FOL1, the second folding line FOL2, thethird folding line FOL3, and the fourth folding line FOL4 extend in thesecond direction (Y-axis direction), the length of each of the firstfolding area FDA1 and the second folding area FDA2 in the firstdirection (X-axis direction) may be shorter than the length in thesecond direction (Y-axis direction). Further, the length of the firstnon-folding area NFA1 in the first direction (X-axis direction) may belonger than the length of each of the first folding area FDA1 and thesecond folding area FDA2 in the first direction (X-axis direction). Thelength of the second non-folding area NFA2 in the first direction(X-axis direction) may be longer than the length of each of the firstfolding area FDA1 and the second folding area FDA2 in the firstdirection (X-axis direction).

The display device 10 may include a first display area DA1, a seconddisplay area DA2, and a non-display area NDA. A number of sub-pixelsSP1, SP2, and SP3 per unit area in the second display area DA2 may beless than a number of sub-pixels SP1, SP2, SP3 per unit area in thefirst display area DA1.

The first display area DA1, the second display area DA2, and thenon-display area NDA may be disposed on the front surface of the displaydevice 10. The first display area DA1 may overlap the first folding areaFDA1, the second folding area FDA2, the first non-folding area NFA1, thesecond non-folding area NFA2, and the third non-folding area NFA3.Therefore, when the display device 10 is unfolded, an image may bedisplayed in the first folding area FDA1, the second folding area FDA2,the first non-folding area NFA1, the second non-folding area NFA2, andthe third non-folding area NFA3 of the display device 10.

Although it is illustrated that the second display area DA2 is disposedin the third non-folding area NFA3, the present invention is not limitedthereto. The second display area DA2 may be disposed in the firstnon-folding area NFA1 or the second non-folding area NFA2.

When the display device 10 is folded in a Z-folding manner as shown inFIG. 24, an image may be displayed in the first display area DA1 and thesecond display area DA2 disposed on the front surface of the thirdnon-folding area NFA3 of the display device 10.

Although some example embodiments of the present disclosure have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the disclosureas set forth by the accompanying claims and equivalents thereof.

What is claimed is:
 1. A display device, comprising: a display panelcomprising a first display area comprising first sub-pixels to displayan image, and a second display area comprising second sub-pixels and atransmission area adjacent to the second sub-pixels; and an opticaldevice overlapping the second display area of the display panel andconfigured to detect light incident through the transmission area,wherein each of the second sub-pixels comprises: a first contactelectrode; a second contact electrode located apart from the firstcontact electrode; and a light emitting element between the firstcontact electrode and the second contact electrode.
 2. The displaydevice of claim 1, wherein a first end of the light emitting element isconnected to the first contact electrode, and a second end of the lightemitting element is connected to the second contact electrode.
 3. Thedisplay device of claim 1, wherein the display panel further comprises:an encapsulation layer on the first contact electrode and the secondcontact electrode; and a sensor electrode on the encapsulation layer. 4.The display device of claim 1, wherein a number of light emittingelements of a first sub-pixel of the first sub-pixels is greater than anumber of light emitting elements of a second sub-pixel of the secondsub-pixels.
 5. The display device of claim 4, wherein a length of afirst sub-pixel of the first sub-pixels in a direction is longer than alength of a second sub-pixel of the second sub-pixels in the direction.6. A display device, comprising: a display panel comprising a firstdisplay area comprising first sub-pixels to display an image, and asecond display area comprising second sub-pixels and a transmission areaadjacent to the second sub-pixels; and an optical device overlapping thesecond display area of the display panel and configured to detect lightincident through the transmission area, wherein each of the firstsub-pixels comprises a first light emitting electrode, a second lightemitting electrode on the first light emitting electrode, and a lightemitting layer between the first light emitting electrode and the secondlight emitting electrode, and each of the second sub-pixels comprises afirst contact electrode, a second contact electrode located apart fromthe first contact electrode, and a light emitting element between thefirst contact electrode and the second contact electrode.
 7. The displaydevice of claim 6, wherein the display panel further comprises: anencapsulation layer on the second light emitting electrode; a sensorinsulating film on the encapsulation layer; and a sensor electrode onthe sensor insulating film.
 8. The display device of claim 7, whereineach of the second sub-pixels comprises: a thin film transistorcomprising a gate electrode, a source electrode, and a drain electrode;a first alignment electrode electrically connected to the drainelectrode of the thin film transistor and contacting the first contactelectrode; and a second alignment electrode located apart from the firstalignment electrode and receiving a first driving voltage.
 9. Thedisplay device of claim 8, wherein the first alignment electrode and thesecond alignment electrode are on the sensor insulating film.
 10. Thedisplay device of claim 8, wherein the sensor electrode, the firstalignment electrode, and the second alignment electrode are made of asame material.
 11. The display device of claim 6, wherein the displaypanel comprises: a second substrate on the second light emittingelectrode; a thin film transistor on the second substrate and comprisinga gate electrode, a source electrode, and a drain electrode; a firstalignment electrode electrically connected to the source electrode orthe drain electrode of the thin film transistor and contacting the firstcontact electrode; and a second alignment electrode located apart fromthe first alignment electrode and receiving a first driving voltage. 12.The display device of claim 11, further comprising a sensor electrodelocated apart from the first contact electrode and the second contactelectrode.
 13. The display device of claim 12, wherein the display panelfurther comprises an insulating film covering the first contactelectrode, and the second contact electrode and the sensor electrode areon the insulating film.
 14. The display device of claim 12, wherein thesecond contact electrode and the sensor electrode are made of a samematerial.
 15. The display device of claim 11, wherein the display panelfurther comprises a filling layer between the second substrate and thesecond light emitting electrode.
 16. The display device of claim 11,wherein the display panel further comprises: an encapsulation layer onthe first contact electrode and the second contact electrode; and afilling layer between the encapsulation layer and the second lightemitting electrode.
 17. The display device of claim 11, wherein thedisplay panel further comprises: an encapsulation layer on the firstcontact electrode and the second contact electrode; a wavelengthconversion layer on the encapsulation layer; and a color filter layer onthe wavelength conversion layer.
 18. The display device of claim 6,further comprising a circuit board on a surface of the display panel andmounted with the optical device.
 19. The display device of claim 6,wherein the optical device is attached to a surface of the displaypanel.
 20. A display device, comprising: a first substrate; a first thinfilm transistor on the first substrate and comprising a first gateelectrode, a first source electrode, and a first drain electrode; asecond thin film transistor on the first substrate and comprising asecond gate electrode, a second source electrode, and a second drainelectrode; a first electrode electrically connected to the first sourceelectrode or the first drain electrode of the first thin filmtransistor; a light emitting layer on the first electrode; a secondelectrode on the light emitting layer; an encapsulation layer on thesecond electrode; a sensor electrode on the encapsulation layer; a firstalignment electrode electrically connected to the second sourceelectrode or the second drain electrode of the second thin filmtransistor; and a second light emitting element electrically connectedto the first alignment electrode, wherein the sensor electrode and thefirst alignment electrode are made of a same material.